I had a windows installation that was essentially non functional (RPC process terminating unexpectedly, which caused an automatic reboot, even in safe mode) I brought out the XP install disk and attempted a repair install. The text-mode phase completed successfully, but after rebooting into graphic mode it is stuck at "39 minutes" Windows is running it's busy indicator and cycling features, but I don't see any hard drive activity.
I've run hardware diagnostics, scandisk, chkdsk, etc. and no errors were detected in either the system or the drive.
Update: After letting it run overnight, I get an error message:
Error: The signature for Windows XP Professional Upgrade is invalid. The error code is 426. The service has not been started.
Fatal Error: Setup failed to install the product catalogs. This is a fatal error. The setup log files should contain more information.