Java won't verify/work after turning UAC back on!

I turned off UAC and then got a virus/spyware I think and I think I got rid of it. Then after turning it back on yesterday to find out now my Yahoo mail icons either a) will not work, b) will bring up a weather forecast box for yahoos weather and will ask me to enter a zip code, or c) if I run as administrator, it will try to go to mail, but just hang for about 5 minutes and finally make it into my mail!

I noticed when I went to install Java (both offline and online versions) that WITH UAC ON, it will NOT verify. WITH UAC OFF, everything seems fine and it verifies.

Well, this bothers me because I am too afraid and do not want to run my Vista with UAC off anymore, and I simply cannot afford to reinstall Vista.

I also noticed while looking at java properties, that there was an unknown user
which mean there was some other user but now that user has been deleted right?

I am the only person that uses this PC and I have never made any other user
accounts, so it must have been a hacker.

Please, I searched for days on how to try and fix this and I reinstalled Java and Yahoo and some other programs over and over again running them as administrator and nothing seems to fix the problems I am having.

Thanks if anyone can help!