This has probably been asked but I certainly didnt find a solution. My pc was running fine. But I had decided to reinstall Windows xp Pro to clean everything out. Poppin in the cd and doing the usual goes perfectly. Formatting the hd, copying the files and then a restart. The system fires up and gets to the NVRAM part and then screen goes black and shows the blinking cursor. That is when the Windows XP logo should show up. But instead, the system reboots again. My pc is sitting in an air conditioned room with upteen cooling fans inside. I monitor the temp in the bios and everything looks fine. I can hit f2 for bios, f8 for safe mode, f12 for boot sequence. ALl work okay. I reseat the ram. No PCI cards installed. One 320gb HDD is installed as a master sata. Everything is pretty much default. Didnt have problems when I got it two months ago and installed xp. When I try doing a repair with the cd at command prompt, I check the C:/ directory and the files are there. I even tried FIXMBR and that just gave me an error upon reboot. Intel Celeron D 3.46ghz 2gb ddr ram 320 gig hdd

A long shot in the dark, but reseat the SATA cable that goes to the motherboard. If that doesn't help, switch the drive to another SATA channel by plugging it into another SATA connector. If that doesn't work, totally unplug the drive and the CD/DVD drive altogether and see if it still reboots, or gives an error about not finding a boot device instead. If it throws the error instead, turn off the PC and reconnect the DVD drive and turn back on. If it seems to be working, turn off again and connect the hard drive. Make sure you ground yourself before working inside the PC and make sure to unplug first. If you've been formatting with the Quick NTFS format, boot up with the XP CD again and do the regular NTFS format. WinSimple Software

Did you remember to install Sata/Chipset drivers. If Safe Mode works, you should be able to troubleshoot in Device Manager. Why are you reinstalling XP PRO after only 2 months? There is nothing to learn from someone who already agrees with you.