Hey, kids. I've got a problem here at work with a computer that I've been using for a little over a year. Here are the specs: Mobo: Gigabyte 8IPE1000-GL (rev.4); Intel i865P/i848P chipset CPU: Intel P4 (Prescott) @ 2.4GHz, 533MHz FSB, 134MHz FSB Freq. RAM: 512MB DDR-SDRAM (x4) GPU: nVidia GeForce 6200 (256MB) HDD: Maxtor 6L160M0 SATA (164GB) PSU: Eagle 400W OS: Windows XP, SP2 So I've used this thing just fine for about a year now, no problems. Seeing as how this computer is my work machine, I needed to upgrade the CPU, because of all the Photoshop/Illustrator work I do. So I decided to get an Intel P4 3.4GHz 800MHz FSB. I installed the chip and the fan perfectly, and booted up. The computer POSTs and enters Windows fine. But I noticed that it completely locked up after five minutes. I rebooted, and tried again. This time, I lasted ten minutes before I had to reboot. Upon the third boot, I did nothing but browse the internet (Firefox 2.0), and I thoroughly enjoyed thirty minutes of that. But once I tried to do something that involved "real" math - archiving some files using WinRAR, calculating the scale of an object in Illustrator, or using my RIP - the computer would freeze. I then removed the new CPU and replaced it with the original, which is working fine. I'm usually pretty good at troubleshooting my own problems, but I have to admit that I'm stumped. I changed absolutely nothing except for the CPU, and I really have no clue as to what's going on. Any ideas?