First off, here are my specs: AMD Athlon 64 X2 3.0GHz Socket AM2 125W Dual-Core Processor ASUS M2N-SLI Deluxe AM2 NVIDIA nForce 570 SLI Motherboard EVGA 640-P2-N829-AR GeForce 8800GTS 640MB 320-bit GDDR3 PCI Express x16 2x Western Digital Caviar Blue WD800JD 80GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive Patriot Extreme Performance 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Windows XP Pro (SP 2) Obviously, this is my first post here. After reading through the boards, I didnt really find a post that was exactly the same as the problem I'm having. If there is a thread with the same problem in it somewhere, I apologize in advance for missing it. There seem to be some great minds here, so I'm sure there will be some great insight, I appreciate it in advance. I'm generally pretty computer savvy. I built my computer and have built / repaired many for an endless list of friends / family / random people. Regardless, I'm very much stuck on what my current problem is. Here is what happened: I was watching my TV when I noticed that my computer had locked up (the screen saver was no longer moving). Upon rebooting the PC (in what would become multiple attempts) the computer would continue to freeze. Sometimes it would freeze during BIOS, sometimes it wouldnt even post. I left the computer off for a couple hours and upon rebooting it again, it fully loaded windows. After about 2 mins of uptime it finally froze again. This seems to be the theme. If I let it sit for a hour or two, the computer will get further in the boot process (most of the time not into Windows, but freezing while loading windows). I've done everything I can think of. I've completely unplugged both my HD's and tried to boot from a Windows CD, it still froze. I've cleaned the entire case of any build up of lint / dust / whatever, still freezes. I cleaned off / replaced the thermal compound on the CPU, still freezes. I've replaced the PSU, still freezes. I've replaced the RAM, still freezes. I've also tried clearing the CMOS (although I didnt replace the battery itself), it still freezes. All the lights on the mobo, fans, case come on when you power up the Computer; also, all the fans are running properly (including the heatsink on the CPU / Video Card). Everything is running as it should when you power up. I think I've narrowed it down to the Mobo or CPU (possibly the Video Card), but I dont really know what to do. I dont have a Mobo, CPU, or Video Card readily available to swap out, and seeing as how they're the most expensive parts, dont want to go buy one only to figure out its not the problem. I know that its generally a tough question to answer, but seeing as how the computer gets farther into the boot process the longer it sits, its kinda throwing me for a loop.