Unity crashes at anything (almost literally)

Unity was running just fine for the first days I’ve been using it, I haven’t changed any of my computer’s settings or updated Unity but now it’s crashing for almost no reason at pretty vital places.

The things it crashes about increases over time, as well.

At first it only crashed when I was changing height map and resolution of the terrain, now it crashes when I try to create terrain at all as well. Sometimes it crashes when I try to delete main camera. There are other crashes here and there but now that I can’t even start the setup of a project, I don’t really notice them anymore.

How do I fix this?

My computer:
64-bit Windows 7 professional on an HP Pavillion dv7 Notebook PC with an Intel Core i7 CPU (first generation, Q720 @ 1.6GHz), 8GB of RAM, ATI Mobility Radeon HD 5650 graphics card.
I have scanned for viruses and none were present.


EDIT!

I started running Unity in compatibility mode for Windows XP SP3 and the program seems a LOT more stable, no crashes observed as of yet. I’ll just leave this here just in case someone else is having similar issues.

My Unity also crashes at anything… I cant work for more than 5 mins litteraly (no exageration). It doesnt come up with a error message it just freezes and I have to use task manager to see that it is not responding.
Hope someone knows how to fix this because I cant get ANY work done.
Nothing to do with project as it is a brand new project.
Help please