I was unsure if it would work at all on windows 7 so I tried a base install of just oblivion with the v1.2.0416 patch. I start a new game, create a character and then start in the dungeon like normal and about 5 seconds later the game will CTD instantly when it makes the first autosave. I've tried installing the game in the ProgramFiles, the x86/Programs files folder and a seperate directory but it still crashes.

I'm using just the original retail copy my system specs are:
64 Bit Windows 7
i7 965
Gtx 480
6GB Ram
ASUS Xonar DS soundcard

Is there somthing i've missed that needs to be done to get oblivion working on windows 7?

Nope. You're doing it right, and your computer is adequate.

However, if your first install was to the default "program files" directory, you probably didn't get it entirely uninstalled.

Uninstall guide: http://www.gamesas.com/index.php?/topic/561101-unofficial-technical-faq/page__view__findpost__p__8103714

If that doesn't seem to be working, look through the Stickied Tech FAQ at the top of this forum.

Pay special attention to programs running in the background, Oblivion doesn't like to share.