Since a few days I got an problem with Graphics. Most of the time everything is just fine, than, using an second, third or more apps, everything on display slows down, and moving the mouse or typing, each movement stacks a little (around 1 sec). Using an Nvidia 640GT with 2GB Memory, I updated to the latest driver: still the same, no difference! Scanned the machine with several AV apps, online an local, all ok NO virus, NO malware, NO trojan, just all is clean! Any idea what could trigger that problem? Thanks for any information.