Hello, I have a Dell Optiplex 745 (160 GB HD and 8 GB RAM) which originally came with Vista 32 bit preinstalled. I received Windows 7 Professional as a gift. i performed a full install on the machine. 7 runs fine on the machine except that the system freezes up after a few hours of operation. I updated all the drivers via reviversoft.com but the issues is still recurring. Has anyone had this issue? Many thanks for your time.