Alan Michka

A: There's no simple answer to this question, but fortunately the likelihood of a disaster resulting is small.

Windows keeps a counter in the Registry for each file that may be shared by multiple programs. When you install a program that uses that file, the counter goes up by one. When you uninstall a program, the counter goes down by one.

When an uninstall brings a file's counter to zero, you get the message that you describe because Windows thinks you're removing the last program that uses the file. But Windows isn't always correct in its assumptions. Installs and uninstalls do not always progress smoothly, and it's possible for the counter to be wrong.

So what should you do? If you're worried about hard drive space, click Yes To All and delete that shared file and any others the uninstall routine finds. The chances of a problem are slight, and if one does come up, reinstalling the first program that complains about the missing file should put the file back where it rightly belongs.

If you're not too concerned about hard drive space, click No to All and leave the files where they are. Beyond taking up some hard drive sectors, they won't do any harm.

By Lincoln Spector