Ok, from your question, it is hard to deduce your problem. You need to give more of your cnfiguration.
However... 99% or at least a goodly chunk of blue screen/straight reboots are driver related.
This will save your life (slight exaggeration?)
How to solve Windows system crashes in minutes - Network World
Read the whole thing & understand it before you act otherwise pay a nice man to do the same - but it should be within the average users capbility.
But to get as far as using the fix, you need to get as far as windows without rebooting, so you need safe mode. I haven't been there for a while, but IIRC hit F8 on boot& the option should present itself.
Good luck!