Random Win7 glitches.

Greetings !
So I bough Win7 HP few days ago and installed it, I chose win7 64 bit. Everything seemed fine...
Then I noticed my cursor stopped , and I thought it was my mouse problem but as I moved my mouse over icons they flashed and I could click them, so first thing I did was to check for drivers. I'm using Trust Predator GM-4600 and all I found was win7 32 bit drivers. It happens quite randomly, and after I reboot it happens again, then for some time it's ok and then again . Maybe someone has solution ? I thought about buying a new mouse maybe but I don't know if it's really the mouse problem.

The second thing that's bugging me is freezing while watching a movie on WMP, I don't know is it WMPs fault or again something else. I'm watching a movie and suddenly the screen freezes and sounds continues for a while and then goes back to normal, or the wmps screen goes black or the movie starts to lag.
Maybe it's my RAM fault ? At the moment I only have 2 gigs DDRII 800Mhz but another 2 are coming today.

Hope someone can help me out a little.
Cheers.

Little bump.
I noticed that the disc check wont start because of an error .
Also it says that it won't start due to recently installed Software package.

Today I tried to run windows 7 32 bit, after a few hours again cursor won't responds, I know this seems like a little problem but it forces me to reboot my pc, which ain't good ( I also bought new mouse with 64 bit drivers and it didn't work ).