After installing the latest system updates for Windows XP, my computers go into a reboot loop. They boot to the XP splash screen, then reboot. I cannot boot into safe mode, and if I use "use last known good settings", I get the same problem. This has happened on two computers in the last two weeks. Both worked fine, with the SP2 update, until I loaded the latest updates. I had to reformat and reinstall XP on both computers and turn off the updates. There are no viruses, and the two computers have different hardware. Help!!