Hi, I recently replaced the original Athlon XP 2600+ cpu with an Athlon XP 3000+ cpu. The computer os is WinXP Pro SP 2, motherboard is an Asus A7N8X-X, RAM is 1G Kingston. Computer ran normally for a week or so and then developed the following problem. In Normal Mode the computer locks up in about 5 to 10 minutes or Reboots. In Safe Mode with Networking, the computer is perfectly stable and connects to the Internet. I have run Spybot and F-Prot anti virus programs which removed a number of malware. In the BIOS, I have tried going to default settings and other options but the problem remains unfixed. It seems that my options are reinstalling the XP 2600+ cpu and/or reinstalling WinXP Pro as I still don't know whether I have a software or a hardware problem. What do you suggest? Thanks in advance for your help. Mike Eisenstadt Austin Texas Visit our website regularly for FAQs, articles, how-to's, tech tips and much more http://freepctech.com