I am considering the purchase of the MacBook Air (AAPL). If this computer freezes up, as my current Dell Inspiron does on occasion, how would I correct for that? I usually remove and then replace the battery on the Dell (DELL). But what would I do if this happens with the Air, since it has no removable battery?

You can force a frozen MacBook Air — or any current Mac laptop — to shut down and restart without removing its battery. You just hold down the power button for a few seconds until the machine shuts off, then wait a few seconds, then turn it on again.

I am a Verizon (VZ) customer and have a Palm (PALM) Treo 700W for personal use. I would like to replace the Treo but, in light of Verizon’s announced “open network” policy, I am wondering if this is the right time.

It’s far too early to know what new phones will be available under the new Verizon program, since that depends on which phone makers decide to make devices to run on the “open” network, and what kinds of devices they might produce. There is the potential for phones that are more creative or interesting than what is available today, but it’s only a potential. Verizon has just laid out the first details of the plan, and no product announcements are likely for quite a while. If your Treo needs replacing soon, and you want to remain a Verizon customer, you will have to choose from the company’s current smart-phone offerings.

Are there any cellphones that allow for two separate phone numbers? Right now I carry two devices, both with the same carrier.

At least in the U.S., each cellphone, or each SIM card that goes in a phone, is normally tied to a single number. To use two numbers on a single phone, you could purchase an unlocked phone running on a GSM network and then purchase two SIM cards, each with a separate number, and swap them in and out. But that would be an inconvenient process, since inserting and removing SIM cards typically requires opening the phone and even removing the battery.

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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 alphabetizing your favorites in Explorer, using Linux as an operating system, and whether Dell is offering Windows XP as an alternative to Vista.

I followed the instructions you printed last week for alphabetizing the Favorites in Internet Explorer, but they didn’t work for me. I am using IE 6 in Windows XP on a Dell computer.

In IE 6, it only works if you display your Favorites list using the menu command, not the icon.

You often mention the Macintosh as an alternative to Windows, why don’t you recommend the Linux operating system?

I aim my columns at mainstream users doing typical tasks who have little or no technical knowledge, no help from experts, and no appetite for becoming techies. These folks want the computer to do things for them. They don’t want to have to do much, if any, configuring of, or maintaining of, their computers. They have no patience for geeky procedures. For instance, when they buy a peripheral device, they expect to plug it in and find that it works, often without even installing the CD from the box. I don’t believe Linux is yet simple enough and automatic enough and nontechnical enough for these mainstream users. So I don’t recommend it. I firmly believe that the Macintosh does meet these criteria, and so I consider it the only practical alternative to Windows for mainstream, nontechie users.

My friend claims that Dell has now decided to resume offering Windows XP as an option on its consumer model computers, instead of only offering variations of Windows Vista. Is this true?

Yes, Dell announced last week that it is bringing back XP as an option on a handful of its consumer laptops and desktops. The models include the Inspiron 1405, 1705, 1505, and 1501; and the Dimension E520 and E521. A quick check of the Dell Web site shows at least one other consumer model available with Windows XP, the XPS 710 — Level 1.

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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