I have Windows XP (all the latest patches) and SystemWorks 2004 (all the latest patches and definitions). SystemWorks Virusscan was run (systemwide on all files) just before Disk Doctor, with no viruses found.

I ran Disk Doctor with the "repair" box checked. The system instructed me to allow it to reboot, which I did. On restarting, it ran what appeared to be checkdisk, with no problems found. Then it rebooted. It is now in a reboot-checkdisk-reboot loop. (I have run this program many times and this is a new problem.)

I can stop the system by holding the ON button for 8 seconds. After I restart it, the problem resumes. [Probably unrelated: following the abnormal shutdown, it offers Safe Mode as a startup option. When that is selected, it hangs after loading agp440.sys (video driver?). After repeating the same abnormal shutdown and allowing a normal startup, the system resumes the reboot-checkdisk-reboot loop.]

Two questions: (1) how can I stop the loop? (2) what is causing this?

Thanks!