It looks like I've found (with some help) the solution to my problems. It appears that my power supply was not powerful enough to run my graphic cards to allow me to play my games. My power supply was like 240 Watts and I need 400 or so to allow the machine to use the graphic cards.
240W ? Wow. That's low indeed. I haven't had such low PSU since....oh one of my office PCs had one, but that was a super PSU (Seasonic), probably the best i ever had.
Be quiet usually does good ones as well.
Nowadays you usually need 350-480 minimum for games and proper use of the graphics card.
If you buy a new one, please don't buy a china cracker. It's really worth the investment of a few bucks more to get a quality one.
Thanks for reporting.
