I'm at a loss here. Have been working on this thing for days. I have finally installed all of the updated drivers of every component and device that is in this thing. It took forever because of the CPU lag. This happens right at start up so its very difficult to install anything on this thing. It seems that CPU @ 100% is usually caused by old or incorrect drivers and I believe I have eliminated that as an issue now. It is a brand new computer so there is no virus or malware problems. I replaced the Hard Drive because I thought that was it because the first Windows load just went to a black screen forever. Does a bad CPU normally do this sort of thing? I hate to buy another one for no reason. Does bad memory cause the CPU to max out constantly? The only thing that I can think of is the motherboard is either bad or not liking the Windows 7 OS. Although it is compatible with it and I installed the Win 7 drivers. Any experts have any advice for me before I toss this thing? Looking at the resource manager the CPU is normally split between the system and the system interupt. Here is what is in the PC: ZOTAC GF6100-F-E Motherboard AMD Sempron 140 CPU WD Caviar 500GB Hard Drive 4GB G Skill DDR3 1333 RAM - F3-10600CL9D-4GBNT ASUS DVD Burner Windows 7 64-bit Prof Nothing else is installed into this thing no software other than all the Drivers. Can't figure this out and any help would be appreciated.