I am running Win 7 64 on a built PC. I had a gforce 9500 and 4 gigs of RAM on a Asus M4A77TD mobo. I upgraded to a GTX 550 Ti 2g and 8 gigs of 1600 RAM. Just before I upgraded and the partial reason for the upgrade was the 9500 was making a weird grinding sound and the com started losing signal to the video card and the usb connections (Keyboard and mouse). I thought installing the new equipment would fix the issue, but alas it has not. Its not after anything specific that it happens. I was running a game for 2 hours and it happened, I also left my comp on over night and it happened when I got up in the morning. It would seem to be more a time or length of time the computer is on that it will happen. Any thoughts, help or solutions? Thanks guys!