Anyway I recently formatted my hard drive and then installed fallout 3.
When I started up fallout it says without launching "application configuration is incorrect."

Have you tried to google your error message? I did and this is one solution: http://forums.2kgames.com/showthread.php?6327-Application-configuration-is-incorrect

Probably did not install all your drivers. The motherboard ones are frequently overlooked as Windows has some that work generically on any Mobo to get the OS installed. So, we think things are fine until we play a game. Get them from the manufacturer's website. Pay attention to BIOS revision issues, if any, on an older board with those drivers. No need to throw a BIOS update onto a machine that was working before the OS wipe.

I already tried that but it now it is saying my Cpu is a 1.40 Ghz when it is a 2.80 Ghz.
now I'm getting mad because it wont even run minecraft!!! (My Only Other Game).