Help! Computer Restarting On It's Own! Back in Nov I purchased a new graphics card and 2 sticks of memory. I've been playing inside computers for a long time, and so I knew my way around the tower pretty well. I installed the new upgrades myself, and removed the old ones. I went from a nForce 5500 PCI to a nForce 6600 GT AGP in graphics cards, and then from 512 PC2700 to 2 sticks of 512 PC3200. Everything worked great for about a month, until I started getting random blue screen errors. Most of the time it told me that it was a "Device Driver Error" but all my drivers were up-to-date. Long story short, after about 3 months, it finally went dead and the operating system was corrupted. Being wise, I had backed up everything once it started doing the blue screen errors, and so I simply reformatted the hard drive. It's been two weeks since the reformat, and there hasn't been a single problem, until last night. The PC froze, and so I simply restarted it. Once I did that, it would try to load XP and restart automatically. I tried running checkdisk from my Windows CD, but it would freeze on me. So finally, I thought it might be the memory which was messing up the Hard Drive, and so I put the old PC2700 back in by itself. This allowed me to finally get to the XP Log In screen. However, once I logged in, I would get to my desktop and the PC would restart automatically. Once more, I whipped out the Windows XP disk and ran CHKDSK. It took two hours and found "two or more errors on the volume." This promted me to run CHKDSK /r for repairs. After another 2 hours of scanning, it finished, and I assumed that fixed whatever errors I was having...wrong! So now I'm not sure if it's the memory, the hard drive, or both...or maybe even something else. Has anyone experienced this before? Should I get a new Hard drive and try using that? Would changing the memory from PC2700 to PC3200 have anything to do with it? Could it be a power supply problem due to the introduction of the 6600 GT? I only have a 300 W power supply... Someone please help me, so I know what I need to buy!