You should be able to use unlink on a PC, so there must be something else wrong. Without knowing anything about what you're doing, it's hard to say.

Are you using die with $! to show you why the system couldn't perform the unlink? e.g.
unlink $file or die "Can't delete $file, $!"

If not, add that and see if it doesn't give you the help you need. If you reply to this thread again, you'll save a lot of time by explaining what you are doing in more detail and including some relevant code.