Fast Forward's Help File

Q If I try to install my old copy of Office XP in Windows Vista, will I run into any prohibitions or technical problems?

AMicrosoft says every version of its productivity suite since Office 2000 is "supported" in Vista, but Office 2000 and XP won't get any bug-fix updates for problems they experience in Vista.

In other words, you're on your own. Multiple readers have told me they've had no issues running Office XP in Vista, so you should be fine running it on the new computer.

Installing it may be trickier. Office XP's "product activation" feature, intended to stop people from using Office without paying, will notice when your copy has been put on a new machine and ask you to reactivate it. Call the phone number listed on the screen; after you explain to a Microsoft representative that you've removed the copy from the old machine, you should get a new activation code.

This approach won't work with an OEM (original equipment manufacturer) copy that the old computer's vendor bundled with the machine. Those are only licensed for use on a single PC. If you'd rather not pay Microsoft for a newer version of Office, try the free, open-source OpenOffice ( http://openoffice.org) or, if you have a broadband connection, the free Web-based productivity suites offered by Google ( http://docs.google.com) and Zoho ( http://zoho.com).

One of Apple's software updates won't install -- Mac OS X says it couldn't verify it. Redoing the install through Software Update didn't help.

If a file gets corrupted on its way to your machine, Software Update may not think to download it again. If that happens, you can get a fresh copy from Apple's Web site ( http://apple.com/support/downloads); once it's downloaded, double-click the file to start installing the update.

Rob Pegoraro attempts to untangle computing conundrums and errant electronics each week. Send questions to The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 orrobp@washpost.com. Turn to Thursday's Business section or visit washingtonpost.com anytime for his Fast Forward column.