Problems uninstalling ad-aware 2007?

ok so for months now ive been having somethin pop up on my computer that says...interactive serives dialog detection,a program cant display a message on your desktop...and it says the program path is from adaware if i click remind me later or just x out it will go away and come back a few mins later...but if i click on show me the message it will go to a unhandled exception or somethin like that...it will say it occured in awwservice.exe or somethin and gives me the option to send crash report or dont send...is this a virus comin from adaware tryin to get in my comp? i dont understand...and how would i go about uninstalling it? when i try to uninstall it somethin will pop up and says a unidentified program needs access to your computer...so ill click ok and it will start to try and uninstall it, and it just wont do anything and eventually a message will come up and say "error 1921 service ad-aware 2007 service (awwservice) could not be stopped. verify that you have sufficient privledges to stop system servies" ....so what do i do?