Blue Screen Of Death after using cubase

So i just recently purchased cubase 7 and was getting familiar again with the product. Out of nowhere it crashes and gives me a blue screen using the crash dump? I was in the middle of messing with vst sounds and since then it has happened about 8 more times, just happened before when i was done using cubase i hit “x” to close the cubase window and it crashed?!?!?! what could be the problem? Idk What to do i just want this to work so i can use cubase stress free right now, still learning the system and this is making it very frustrating. also im using windows 7 8 gb of ram, 64 bit, idk my sound card sorry