Just wanted to let everyone know. I had a user with this same problem. ( winfixer 2005 ). I searched the registry for the following: atea, winfixer & uwfx5. Deleted all instances of these key's, as well as deleted the cookie & the shortcut on the desktop & it's no longer coming up. Prior to this I also installed a trial version of McAfee Spyware Blocker which didn't fix the issue on it's own, but found the files.
You may wish to look in c:\windows for a file: nail.exe
If it is not there, you should be in good shape. If it is there, then the aurora adware is still there and stuff like winfixer will keep coming back.