Is Security Prudent for a Smart Phone?

There’s no other major item most of us own that is as confusing, unpredictable and unreliable as our personal computers. Everybody has questions about them, and we aim to help.

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 security for smart phones, finding desktop computers with Microsoft Vista Ultimate preinstalled, and changing iTunes authorizations.

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Having recently switched to a Windows-based smart phone (Treo 750) which has sensitive information on it, I am concerned about the need for antivirus and firewall security. Is security prudent for these phones?

First of all, the “Windows” on your phone isn’t in any way the same software as the “Windows” on your computer. Programs, including viruses and spyware, which are designed to run on a Windows PC typically won’t run on a Windows Mobile phone. There is some evidence of malicious software infecting phones, but the problem is quite minimal and I don’t see a need to install antivirus programs and firewalls on phones — yet.

I am limping along on Microsoft ME and would like to obtain Microsoft Vista “Ultimate.” I am finding that there are no desktop machines available in the stores that have “Ultimate” preinstalled on them. They all seem to have Vista Home Basic or Home Premium. Why is this?

Windows Vista Ultimate is the most expensive version, and doesn’t do very much more for an average consumer than Home Premium. But it can be found on some higher-end model computers in stores and can often be specified when ordering a higher-powered computer online from companies like Dell and Hewlett-Packard.

As you know, there is a limit of 5 PCs on which you can store/play your iTunes copy-protected music. I recently donated a PC but forgot to de-authorize it from my list of available computers. Is there a way to accomplish this even though I no longer have the machine?

Yes, Apple allows you to reset your authorizations, either by going to the account settings in iTunes or by contacting them and explaining the situation. The Account page in iTunes is reached by going to the iTunes store, and then selecting “Account” under Quick Links at the upper right. This reset will deauthorize all your machines, but that’s not as drastic as it sounds. It merely forces you to enter your password the next time you play a copy-protected song on any of the computers you want to remain authorized. After that, you’re all set.

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