system blue screens every time windows tries to load

I have a dell xps M1530.
After fiddling with a bunch of settings to get protools 7.3 (an X
program) to work in compatability mode, it wouldnt work after installin
and uninstalling it a few times so i bought the new vista compatibl
version but when i went to uninstall it it wouldnt let me
I then turned off DEP with setup>performance>dep but it didnt work so
disabled it in command prompt but it still wouldnt let me uninstall it
Then after i turned it off the next time i turned it on it wouldn
start. Every time i try to start it it loads up to the start of th
windows load screen where the green bars usually go across the box, bu
after loading the box and the windows logo it blue screens and goes bac
to the initial loading screen
Every time i run startup repair it says there is no problem, the
restarts and does it all again
Every time i run system restore i run it back before i tried installin
protools at all, and it says its successful but then the same blu
screen happens at the same time. When i run system restore it only let
me run it on the OS: (system) drive and the other drives are able to b
highlighted but i cant tick the boxes
Any ideas? thankyou