Uninstall Issues

Have you ever installed a program and then when you uninstall, it keeps the files behind. Or does not do the uninstallation at all? What causes this and what can be done to make sure your computer is clean of the files?

sure it happened to me, mostly with "trojan like" programs, tool bars etc.
most of the free stuff you get from the internet will behave like this - after
all you have nowhere to go, nobody to complain to.

solution? in case it's "real" trojan just run anti trojan scan. in case it's
legitimate program that just won't bother to delete itself you can manually
delete its files from the Program Files folder and search the registry for
anything related to the program, and remove it.

I don't believe there is tool that can "clean" the computer since it can't
know for sure what stuff is legitimate and what isn't.

There are many uninstallers that leave things behind, particularly when you uninstall but didn't close the program in question first.

Some vendors offer tools to clean up leftovers. Otherwise you either leave the junk behind or remove the leftovers manually, as long as you know what to remove.