For Vista you need to set both the installer, then LW to run as Admin. If that doesn't make any difference, go to properties & change compatibility mode to XP. Also delete any LW preferences if any. Fixes for Limewire (click on blue link)

Correct way to uninstall LW is via Start menu -> All programs -> LW -> Uninstall. Else go to program folder & find uninstaller there.

You tried those steps in my first post but couldn't get it to uninstall? What was the error message? How did you try to uninstall it? I'm wondering if it's because it was not set to run as Admin as it needs to be for Vista.