I have a Dell Inspiron 530 with Win 7 32bit, GeForce 9800GT graphics card and upgraded my power supply to Silencer 500W PC Power. My power settings are set never to shut monitor or hard drive. When I play some videos my computer goes into power saver mode and I can't get out of it unless I manually hold the power button for 10 seconds. I never had this problem until I upgrade to Win7 Ultimate from Vista Ultimate. Any suggestions?