If your not allowed to then the process is probably running, hence you are trying to delete a file that is being executed, which you cannot do. If ad-aware wont remove it, run the task manager to see of the file is running and then kill it, then delete the file. Safe mode works well for things like that as well as you have a restricted amount of programs running in the background.

Just a question, Did you not run adaware before? after the like 2nd post when it was suggested?