Report "My Sempron 3000+ at 1.6GHz is shutting down just before loading Windows, only if the booting time is short. If I push the pause button during boot and wait for 3-5 minutes, it will load Windows without any problem. I reinstalled the windows ( now I have Windows7 Ultimate ), but it keeps shutting down. I have a GeForce6100 SM-M motherboard ,1Gb( 2x512) DDR2, dual channel and a 400W power source"