Monte Vista keeps shutting down/ game crashes constantly...is it my pc? or the game?

every time i try to load one of my saved games on monte vista an error message comes up and tells me to restart the application....when i try to restart the application, it wont let me. finally i have to restart my computer. i try again, same error message. no problem starting a new game. until that crashes randomly. which brings me to my next issue...playing monte vista or not, the sims is constantly crashing. ive been a simmer for years and have never had this much of a problem until recently. i cant play supernatural at all. seasons freezes. and monte vista never lets me load games. im starting to think maybe its my laptop? but my laptop works fine for everything else i use it for. if in fact it is the pc, what pc would work best for gameplay? HELP.