So after having a great time on FO3: GOTY on PS3 I decided to go ahead and buy the PC version because the mods looked awesome.
Before doing so I ran a quick check and found that my PC exceeded minimum requirements.
http://img683.imageshack.us/img683/5163/mysystem.png

So after installing Fallout 3 and then the DLC from the GOTY disc, I set Fallouts graphics on low as my graphics card isnt that great (although DOES exceed minimun)

I decided to just have a quick play with no mods at first, so there are no mods running that could be causing this.
I go to play fallout 3 and....

http://img571.imageshack.us/img571/245/fallout3hasstoppedworki.png

Yep, dont even get to initial load screen. Just a black screen and then that pops up.

NEVERMIND, PROBLEM RESOLVED.

Good.