OK, so I have experience with oblivion and fallout and stuff through 360 but since I want to use mods I bought the pc version (bought the GOTY deluxe edition which brings me on a total of about $100 I spent on this game in total) and now that it's downloaded, it crashes on startup
i start the launcher, click play game and it starts up, then crashes after about 5 seconds or if I skip to the loading screen (not main menu) it crashes there the moment it appears.

what is going on here?

Try low video settings or reinstall the game.

Btw can u write ur system?

Absolutely no way to guess, since you chose not to offer any diagnostic information. If you have it on a PC now, you should realize there is no such thing as a standardized desktop machine.

http://www.gamesas.com/index.php?/topic/1123068-what-that-dxdiag-thing-includes/

(That is in the FNV Forum, but the overall principle is the same.)

I did some searching and quickly found the main suspect, i have vista 64 bit.
I did have a torrented illegal copy of the game (minus shivering isles) for a while but thought it was damaged due to noobish mod installing and bought the steam GotY deluxe edition expecting to get a working version. $25 wasted it seems but the illegal did work perfectly for a week or so why not this legal steam version?

does anyone know a way to fix this? I know there are people who can run it with vista64, I've been one of em!

in the Oblivion launcher (with Play, Data Files, Options, etc) see if the boxes in the data files are all ticked or all unticked, cause think its necessray at least the Oblivion.esm is ticked and dont think mine was set up right at first, but could still run the game... Also if you get past the crashing on startup, you might also find the Steam version crashes a bit when quiting. Mine had a 95% chance of doing that until installing the obse plugin FastExit2. A brilliant little mod. Or you could just hit console and qqq for the same effect