av.exe AND win32.exe terrible issues, please help

First off, welcome Major Geeks. I made an account in the hopes that I could get some help from my irritating problem.
I am running Windows Vista.
Just today I was getting annoying pop-ups from an obviously fake Windows Security Center, telling me a bunch of garbage, doing fake scans, and whatnot. After closing the program through task manager it came back, so I found the file location, and noticed that it was hidden. To remove the irritating program I made a .bmp file, renamed it to av.exe, and put it in the folder. When I put it in it asked me if I wanted to replace it, and I said OK. Then, no more problems, no av.exe on my task manager, and it didn't come back. Then the second I tried to open up an application it told me, "(app) is not a valid win32.exe application", or something like that. So I searched for a resolution to this problem on the internet. I went through your 'read first' and installed many programs and whatnot only to be sad upon realizing that none of them could be opened. Some 30 minutes later I had a hunch to delete the new 'av.exe' in my Appdata/local folder, and when I did that I had some new freedom. When I want to run Notepad.exe, for example, instead of saying it is not a valid win32.exe app, it gives me the 'Choose the program you want to use to open this file' box. So i Browse for Notepad, wherever it is, and run Notepad.exe with Notepad.exe, and it comes up. So I was relieved but not finished. I tried to open a program that I downloaded, called FindyKill, for example, but when I browse for it in my download file that is pointless. Because it just asks the same question again and again. Seems I can't download anything....
I'm guessing its a combination of two viruses, but I am unsure.
Help would be greatly appreciated. Thanks in advance.