*cries* I thought i'd solved all my problems

When I save the game, it starts saving as it usually would, but then everything goes black - like it does when the computer is off, and I have to restart as nothing else can be done.
So, basically, saving my Sims game crashes my computer - what the hell could be doing this? I took out all the hacks/mods/careers i'd downloaded in the last day [except for the bigger families one because there may be a problem if I take that out]. Although I get the feeling this may not be to do with downloads...
I'm so sorry about needing help again, I really don't mean to bother you all so much but I really appreciate the help
