I need some help sending videos to others. It seems that every video I try to send in various ways is always too large. I’ve tried to use a program that works with Outlook to compress the email attachment, but it’s always still too large. Is there a solution other than uploading them onto YouTube or something similar?

I suggest you try one of the services that specifically exist to transmit files that are too large for email. They typically work by having you upload the files to their servers, which, unlike YouTube, don’t expose them to the world. Seconds after you upload these files, your recipients receive an email that includes a specific link to the file you uploaded. The email is small because it includes only the link, not the file itself. The recipient clicks on the link, and the file is downloaded to his or her computer.

The service I use for this is called YouSendIt, and can be accessed at yousendit.com. It works in all the major Web browsers, and on both Windows and Macintosh computers. The company has a free plan that covers files of up to 100 megabytes in size, and allows each file to be downloaded up to 100 times, or up to a gigabyte of total downloads each month. For $10 a month, you get a maximum file size of two gigabytes, 500 downloads per file, and a monthly maximum limit of 40 gigabytes.

In my experience, YouSendIt works well. It can be used directly from within a browser, or via a small program called YouSendIt Express, that lives on your computer and handles large files faster than the browser version does. YouSendIt also offers an Outlook plug-in that can automatically route large downloads via the service rather than through regular email, though I haven’t tested this plug-in.

Our daughter is heading off to college this fall. She will be an art/graphic-design major, and the school recommended that she buy an Apple MacBook. I’m not sure if she should get what the college calls the “midlevel MacBook” or the “advanced MacBook.” The only differences are a slightly faster processor, a hard disk that is 40 gigabytes larger, and a “SuperDrive” for CDs and DVDs rather than a “Combo” drive. The price difference is $90. Which should we buy?

Either machine would be fine, and a lot depends on your budget, since college itself is of course very expensive. But I think, in this case, the extra $90 would be worth paying. This has nothing to do with the processor speed, which she probably wouldn’t even notice. But, if she is going to be creating a lot of graphics files, which can be large, the extra hard-disk space could be important.

The same goes for the CD/DVD drive options. The “SuperDrive” is Apple’s term for a drive that can create both DVDs and CDs, while the “Combo” drive can create only CDs. (Both drives can play both types of disks.) For someone who is producing large files, the ability to create DVDs can be handy, since DVDs have much higher capacities than CDs.

My laptop has been infected by rogue viruses, posing as antispyware programs, that I can’t get rid of. When I go on Google, I find a number of sites that claim to offer free software that will get rid of them, but I am reluctant to download anything onto my machine from a source that I am not sure of. What’s a reliable program that will do that job?

I would immediately buy a genuine, legitimate commercial antispyware program, install it and run it. The best ones I know of are Spyware Doctor by PC Tools, at pctools.com, and Spy Sweeper from Webroot, at Webroot.com. Each costs $30, but that price can save you a lot of heartache.

You can find Mossberg’s Mailbox, and my other columns, online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

Do you know of a free or inexpensive program that will overwrite hard drives? My husband and I have updated to new computers, leaving us with two hard drives that have sensitive data that we would like to erase before disposing of them.

There’s a $20 program for Windows called Window Washer from Webroot that will wipe an entire hard disk so that its data is unrecoverable. Its maker calls this process “bleaching.” In cases where you don’t want to completely wipe a hard disk, the program can also securely erase individual files and folders, and can remove all traces of browser activity. I have tested it, and I can recommend it. You can get it at Webroot.com.

There are numerous other Windows file wipers, some of which may be free, though I haven’t tested them. To find these others, go to download.com and enter “file wiper” in the search box.

Since downloading the new Firefox browser, the panel at the top that shows the Web address and the back and forward buttons has disappeared. How do I get it back?

That panel is called the Navigation Bar and it can be turned on and off. It sounds like it somehow got turned off on your computer. To switch it on again, go to the “View” menu, select “Toolbars” and then click on “Navigation Bar.” The missing panel should reappear, and the next time you view that menu option, you will notice a check mark next to “Navigation Bar,” indicating it is on.

You can also use the same technique to switch the Bookmarks Toolbar on and off.

I have switched to Mac recently and never want to use Windows again. But the program I miss using on Windows the most is Microsoft Money. Do you know any way to make this program run on my Mac?

Microsoft (MSFT) doesn’t make a Mac version of Money.

However, all current Macs can run Windows and Windows programs. I suggest you pick up a copy of one of two programs — Parallels Desktop or VMWare Fusion. Both allow you to run Windows programs right alongside your Mac programs, even without displaying the Windows desktop. Microsoft Money would just appear in its own window, as if it were another Mac program.

This method works well, but it carries a price. Fusion and Parallels cost around $60-$70 each, plus you will have to buy and install a full, fresh, boxed copy of Windows.

• You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital Web site, http://walt.allthingsd.com.

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about antispyware software, Powerline adapters and the Mac mouse button.

I set my parents up with a new Dell PC, and included antispyware software that I run periodically to clean up the computer. I recently discovered they had more than 200 instances of spyware on the machine. This may be because my 81-year-old father surfs porn sites ALL the time (this isn’t a joke). Is there any way to keep his computer bulletproof and safe?

Assuming you can’t dissuade him from the porn sites, which are common sources of spyware and adware, your best option is to switch to a type of antispyware program that blocks the installation and operation of spyware and adware programs as it is happening, rather than waiting until they are installed to clear them out. The best program I have tested of this type is Spy Sweeper from Webroot, but there are others. These types of programs usually aren’t free, but their prices are modest and they would allow your dad to spend his golden years as he sees fit.

Last week, you recommended Powerline adapters that can route an Internet connection over the regular electrical wires in your house. I have two questions about these products. If a home has two different circuit-breaker boxes, can adapters plugged into outlets connected to the different boxes communicate? And, could a neighbor who shares an outside electrical line potentially spy on my Internet usage?

I am not an expert on electrical systems, and neither of these circumstances applied to my tests. So I asked Netgear, the manufacturer of the XE104 adapters I reviewed last week.

The company says that if the two adapters are plugged into outlets that are on totally independent electrical “loops,” they won’t be able to communicate, because the electrical current itself wouldn’t pass between the loops. However, Netgear claims it is “extremely rare” for a home built after 1950 to have two wholly independent loops, even if they have two different circuit-breaker boxes. The company says that, at least in newer homes, separate circuit boxes are often linked.

However, I would add that electrical layouts vary so much that there is no guarantee that any two electrical outlets will have a connection that will work with Powerline adapters. I believe it will work in the vast majority of cases, but not all. In my home, which is 36 years old, the adapters did work between rooms with different circuit-breaker boxes.

On the security issue, the company says it is theoretically possible, but very unlikely, for a neighbor on your same outside electrical line to spy on a network running over your interior electrical wires. To do so, Netgear says, the neighbor’s house and yours would have to lack a filter between them, and those are commonly present. Even then, a nosy neighbor would have to know that you have a Powerline network — and buy a compatible adapter — in order to access your network.

This is likelier, but still not very probable, in an apartment building, because circuits in such buildings are often shared. The company does include optional encryption software for such situations, so that even if a neighbor can snoop on you, he wouldn’t be able to decipher your network traffic.

I am thinking of buying an Apple MacBook, but I notice it only has one button below the touch pad, and no obvious scrolling control. Without buying and using a mouse, how can you right-click and scroll on a Mac laptop?

The Mac operating system and Apple software do in fact support right-clicking, displaying the same sort of pop-up menus that Windows does. However, on a Mac laptop with the single button, the traditional method for right-clicking has been a clumsy one: holding the Control key while clicking the button.

Now, the latest Mac laptops have a much easier and cleverer method for right-clicking: you just place two fingers on the track pad and click the button. It’s fast and easy, though still not as good as if Apple abandoned its odd mouse dogma and simply built dual buttons into its laptops.

Also, the new Mac laptops have a method for scrolling that I find superior to the methods common on Windows laptops: you just place two fingers on the touch pad and drag them up or down together. It quickly becomes second nature.

* * *

Because of the volume of email I receive, I can’t routinely answer individual questions by email, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about moving iTunes files to a new computer, file-compressing programs and security software.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

I recently bought an Apple iBook to replace an old Dell laptop. How do I move my iTunes music files from the Dell to the Apple?

Your iTunes music files work on both Windows and Mac machines, as does the special iTunes Library file that keeps track of play lists and the like. So, all you have to do is copy these files from the Dell to the Apple, as with any other files you want to move. In fact, even if you were moving from an old Dell to a new Dell, without changing operating systems, the process would be the same.

If you have allowed iTunes to gather all of your files into the folder called “iTunes” within “My Music,” all you have to do is copy that folder to the iBook. This can be done in a number of ways, but the best choices would be to do this via a home network or by burning the files to CDs or DVDs and then copying them from the CDs or DVDs onto the Mac. On the Mac, the iTunes folder is usually located within the Music folder.

If your music files are scattered, or are in the My Music folder, but not the iTunes folder, you’ll have to locate them before copying them. Be sure to copy the iTunes folder also, because it contains the iTunes Library file.

If you have an iPod and it contains all of your songs and play lists, you can skip these steps. Just download one of the many cheap utility programs for the Mac that will copy the contents of an iPod to a computer. Two examples are PodWorks and PodUtil, the latter of which comes in a Windows version for Windows-to-Windows transfers.

One more thing: Be sure to deauthorize the Dell from your iTunes account before authorizing the Mac, so you don’t waste one of your maximum of five slots for computers that can play any songs you purchase. To do this, fire up iTunes on the Dell, go to the Advanced menu and select “Deauthorize Computer.”

What program do you recommend the most for compression and decompression of files? Winrar, WinZip or any other program?

On Windows, I use WinZip (www.winzip.com), because of its flexibility, even though the operating system can compress and decompress files by itself. On the Mac, I use Stuffit (www.stuffit.com), for similar reasons. A decompress-only version of Stuffit came with earlier versions of Mac OS X, Apple’s operating system. The current version of OS X, Tiger, can compress and decompress files in the popular Zip compression format without Stuffit.

I run Norton Internet Security, Ad-Aware and Spybot on my computer to keep “bad stuff” from infecting my system. Yet last week a malicious program attacked my computer. It hijacked my wallpaper and put a huge warning on my desktop. My security software never knew it was there. Do I need to run additional security on my computer?

This category of spyware or adware is expanding so fast that, even with the two good anti-spyware programs you are using, attacks can happen. My only advice is to add a third, such as Webroot’s Spy Sweeper, which is my favorite. I know this is annoying, but until the spyware/adware epidemic slows down, it is often necessary for Windows users to have multiple defenses.

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about “file wiper” programs that permanently erase a hard drive, staying safe at public wireless hot spots and sorting USB cables.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

The community where I live has a one-month period (April this year) where you can dispose of your old computers. I have several old PCs around the house, but want to clean out the hard drives. Can you recommend a good program that can clean sensitive data off a hard drive?

There are a number of such “file wiper” programs, which permanently delete files so that they can’t be recovered. Some are free, but the one I recommend is called Window Washer and costs $30 from Webroot Software Inc. It can be purchased at Webroot.com and elsewhere. The program, which also performs other tasks, has a file-wiping function called “bleaching.” It can be used multiple times.

Does the security I’ve installed for my home wireless network protect me when I take my laptop to a public hot spot? If no, what can I do to protect against snoopers there? I run both Windows and Apple laptops.

No. The wireless security in your home is a network feature, not a laptop feature. It doesn’t come along with your computers when you use another wireless network. At a public hot spot, you are sharing a network with strangers. So you can’t entirely guarantee your security and privacy from prying or malicious people in the vicinity. However, I would turn off all file-sharing features on the laptop, make sure a firewall is running, and avoid doing anything sensitive online, such as financial transactions.

If one has a box of unlabeled USB cables, is there any way to sort USB 1.1 cables from the USB 2.0 cables? Or is there even a difference?

You can’t sort them, and in most cases there is no difference. Older USB cables that were certified to work on the older 1.1 ports should also work perfectly with the faster USB 2.0 ports. The USB 2.0 standard was designed to work with the same cables as USB 1.1. In fact, I have never seen or used a USB cable, no matter how old, that couldn’t be used at full speed with USB 2.0. However, some cheaply made older cables that weren’t certified might fail.

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about synchronizing bookmarks in Firefox among multiple computers, balancing performance and price when buying a computer and permanently deleting files.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

I was wondering if there is software or a plug-in that would allow me to synchronize my bookmarks in Firefox among multiple computers. I’ve looked but couldn’t find anything.

You can add functionality to the Firefox Web browser by installing small add-ons called extensions. Some of these are designed to synchronize bookmarks among multiple Firefox-equipped computers, over the Internet. I haven’t tested any of them, so I can’t recommend any particular one. But here’s how to find one.

In Firefox, go to the Tools menu, select Extensions, and then click on the link at the bottom of the window that says “Get More Extensions.” This will take you to a Web page filled with extensions and other add-ons of every type. In the search box, type in the word “synchronize,” and you’ll see some choices. You can also browse the category at the left of the page called “Bookmarks.”

Will a high-end computer perform concurrent multiple office tasks (i.e., Word, Quicken, Internet search) faster and more efficiently than a budget computer?

Sure, because a high-end computer, costing more than $1,500, will have more memory, a faster processor and faster internal pathways through which data can flow. Budget models, costing under $500, have slower, smaller, more bare-bones versions of these components. However, there’s a middle path. If you don’t need the very fastest switching among windows or concurrent programs, a midrange, $600-$800 computer with at least 512 megabytes of memory should do the trick. It will handle concurrent programs and switch between them with a delay so slight as to be fine for most users.

How do I delete files on a computer so that they can’t be recovered by anyone else?

When a file is deleted on a computer, the actual contents of the file aren’t immediately wiped out or overwritten. They can still be recovered by an expert, or even a mainstream user with the right software. To completely delete a file, you need a utility that overwrites the space on your hard disk formerly occupied by the files with multiple layers of nonsense data.

On a Mac, this function is built as an optional deletion method. On a Windows PC, you need to obtain an add-on program that does this. The best one I’ve tried is Window Washer from Webroot, available for $30 at webroot.com. It has multiple functions, but the one you need is the “bleaching” function, which permanently erases files.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about switching to DSL from dial-up, browser hijacking and whether to wait for Windows Vista.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

We are satisfied users of dial-up Internet access. Our only complaint is the very slow transfer rate of four kilobits per second when we download updates for our security software. Would a 768 kbps DSL line really download these files almost 200 times faster than dial-up? It costs only slightly more than we pay for dial-up.

Most Internet services don’t actually function at the advertised speed, due to network congestion and other factors. So, DSL isn’t going to operate at 768 kbps. But it will probably run at 600 kbps or more, which is still vastly faster than dial-up. And, since file transfers tend to be the speediest online activity on DSL or cable modem services, you should see a dramatic reduction in the time it takes to update your security software. With DSL now starting at around $15 a month, the same or less than dial-up typically costs, I can’t see any reason why anyone who uses the Internet regularly should stick with dial-up access.

When I click on my browser in Windows XP, I get a page saying spyware is detected, and my computer is under the control of a remote computer. This screen tells me that I can solve this issue by downloading various security programs I’ve never heard of. I’ve tried to get rid of this page by deleting temporary files, cookies, files, programs — anything else I can think of — but it keeps appearing. Neither Norton anti-virus nor Spybot gets rid of it.

Sounds like you have a nasty case of browser hijacking, a type of spyware that seizes control of a browser to try and peddle dubious products that may themselves install more spyware, even though they are posing as security software. The people who invade computers and browsers in this manner deserve to be locked up.

You can’t get rid of pernicious spyware like this by madly deleting files or changing browser settings. Only a strong anti-spyware program can kill it and prevent it from reappearing. But sometimes you have to try multiple anti-spyware programs to get the job done. You’ve already tried one good one, Spybot, which failed. I suggest you go to Webroot.com and download my favorite anti-spyware program, Spy Sweeper. If that doesn’t work, try Ad-Aware or Counterspy.

I am considering buying a PC with the Windows Media Center operating system. But I am wondering if Media Center will be updated when the new Windows Vista comes out. Should I buy now or wait?

The Media Center flavor of Windows is scheduled to be retired in the fall of 2006, when the new Windows Vista is set to be released. Instead, the key functions of Media Center — including the across-the-room remote control of music, TV, photos and videos — will be folded into some versions of Vista.

If you buy now, and your new machine is hefty enough to run Vista, you should be able to upgrade to the appropriate version of Vista and retain all your Media Center functionality, with some improvements. But you’ll have to pay for the new software.

If you wait 10 months or so, you can buy a new PC pre-loaded with a version of Vista that includes these functions. But you’ll have lost nearly a year of use of the very good Media Center functionality available today. My advice is: If you really need a new PC now, and really want the Media Center functionality now, buy now, and plan to upgrade to Vista later. But, just be sure you get hardware capable of running Vista. For my column on Vista-capable hardware, see: ptech.wsj.com/guide-pc.html.

* * *

Because of the volume of e-mail I receive, I can’t routinely answer individual questions by e-mail, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

Write to Walter S. Mossberg at mossberg@wsj.com

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

Recently, my laptop is taking an inordinate time to boot up. I have tried disk cleanup, defragmentation, and multiple scans by antivirus programs but nothing seems to speed up the full bootup process. Do you have any suggestions?

This probably indicates that you have a large number of programs, many of them invisible to you, that are configured to launch at startup. Some may even be spyware and adware programs. I suggest two steps. First, get a good antispyware program, like Webroot’s Spy Sweeper, and do a thorough scan of your system, deleting all the spyware and adware you can find. Spy Sweeper, which costs $30, is available at www.webroot.com. (A free trial is available.) Then, reboot.

If the system continues to reboot slowly, you should run a program that tells you which programs are trying to launch at startup. Get rid of those you don’t need. A built-in Microsoft utility, msconfig, can do this for you. Just select Run from the start menu and type “msconfig.” Look over the programs listed in the “Startup” tab of the program, and uncheck all that you’re sure you don’t need. This may be tough, because msconfig doesn’t give the English names of the programs or explain what they do.

Even better, download and run a startup utility like Startup Cop, which explains things better. It costs $5.97 and is available at www.pcmag.com/article2/0,4149,2173,00.asp.

We would like to use the Internet wirelessly in our home, but we have a dial-up service. We were told by others that one has to have a cable or DSL modem to go wireless. Is that true?

No, you can do it with dial-up, though the speed is so slow that the experience over wireless may be disappointing. A company called Always On Wireless makes a wireless base station called the WiFlyer that is specifically designed for sharing dial-up connections wirelessly. It costs $150 and is available at www.wiflyer.com. I have seen it demonstrated, and it worked, but I haven’t tested it.

I run Windows XP home edition and also Word. After installing a newer edition of Word, I began to have a problem when I went to look for my newly prepared files. They don’t show up in the folder that I thought I put them in. How can I resolve this aggravating problem?

In Word, go to the Tools menu, and select Options. Go to the File Locations tab, and click on Documents. Set the location for saving documents to whatever folder you prefer, and click OK or Close until you are out of the Options window. That should take care of it.

* * *

Because of the volume of e-mail I receive, I can’t routinely answer individual questions by e-mail, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

Write to Walter S. Mossberg at mossberg@wsj.com