Dell M5510 freezes up with black squares on the screen

I have a Dell M5510. I previously had an issue withe battery swelling up which then caused a MB failure. I have since had dell replace the motherboard. This worked fine for around 2 months but recently I started to have an issue. If I left my computer over night when I came to use it the next day I noticed it was restarted.

After further using the computer I found out that it would start to get black squares on the screen and then freeze. It can even do this on initial boot when it first enters windows. I have also got these black squares on the login page for windows. The squares are repetitive almost in a diagonal across the screen. I will capture a screenshot next time it happens.

Once the black squares happen I have about 0-30 seconds before the whole system will freeze. I wanted to know if anyone can recommend a solution for this or tell me where the problem relies?

I have tried to roll back drivers for the video card and various other items as well.

Thank you