XP won't Reinstall after System Restore failure

From: Neil (anonymous_at_discussions.microsoft.com)
Date: 05/03/04 

Date: Mon, 3 May 2004 09:21:03 -0700

I turned off XP System Restore prior to attempting removal of Sassen virus. I was then unable to turn SR back on. I have tried all of the fixes that I could find on this forum for turning it back on, to no avail. As a last resort, I just tried to reload XP. While the CD was running, I got the following 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 logs should contain more information –
 
When I close the error window, the system always returns to the Install process and goes immediately to the error again. This occurs even if the CD is not in the drive. I have tried Safe Mode but the results are the same. My questions are: How do I prevent the boot to Install? Once I am able to boot again, how do I turn on Restore again?