Random BSOD's And Laptop Freezes?

i have a laptop 3 years now, a Sony VGN-NW21SF. My laptop gives me random BSOD's and often freezes. I dont perform any special operation when these incidents occur. The Laptop may be idle when this happens. Sometimes, i leave the computer turned on, and when i come back either the system has frozen requiring a pwr_btn shutdown, or has restarted with BSOD's. I have no indication on what is causing this, only one suspicion. That my Laptop is not compatible with SSD's. I suspect this because if i remeber correct, these BSOD's and Freezes, started when i first installed an SSD. Then i changed this SSD with another one, but still the problem remained.I have thrown away two ssd's and after i purchased a third one, different brand, different capacity the problems persist... Needless two say that now i feel like an idiot blaming and throwing away two ssd's... Because it can't be 3 ssd's with the same problem..... The other obeservation is that the BSOd may not happen for more than a month, and suddenly it may happen 4 times per day...