Back in the late 90s I worked on a small Windows product... our CEO complained that when the uninstaller ran, it left the empty directory behind along with some small temp files created by the software (that the package hadn't put there during install). So the guy making the package added a command to remove the directory and its contents...

... and the first reporter to try software, for reasons I'll never totally understand, chose to install it in C:\. Worked great until he went to uninstall it.