Removing PassShow EXE Files

I want to remove PassShow from my Windows Vista computer.  I've been able to send all but the exe files to the recycle bin.  When I try to delete the exe files, a message claims I need permission.  I get the same message when I try to use the control panel's uninstall process.  Any other way to get this annoying adware removed?  Thanks for your help,

Bob N.