Pat, here are a few ideas, although I'm definitely not an expert. Have you tried deleting the files within the folder individually before trying to delete the folder? Have you tried right-clicking the file/folder and going to the security tab, then resetting the permissions? You should also make sure you attempt to do all the deleting in safe mode. After trying that, there are futher things you can do, but I would start with those, if you haven't already tried them.
As for removing all leftovers, you can ask for assistance on the Lavasoft forums. They should be able to help you clean out the remaining remnants of Ad-Aware.
http://www.lavasoftsupport.com/
Edited by mintchip, 12 March 2009 - 08:45 PM.