When I try to boot I get the message that the following file is missing or corrupted: \windows\system32\config\system Further I am advised to use the Windows Recovery Console. I understand that if I use Recovery Console to replace the System file (if it works) I may have to reinstall all my applications (nightmare). Is there any way to solve this with less pain? The origin of the problem could be one of these two: a) I recently edited the registry and may have deleted something essential b) I installed PartitionMagic 8 and decreased the cluster size of my main (boot) hard disk (to make it faster and less prone to fragmentation). To do this I had to disable GoBack, so I can't use is now to go back. I have a second hard disk, maybe I could install XP on the second disk, boot and then repair the first disk. Does that make any sense?

ERRORS: missing or corrupt : \WINDOWS\SYSTEM32\CONFIG\SYSTEM, or missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SOFTWARE, or Stop: c0000218 {Registry File Failure} How to Recover from a Corrupted Registry that Prevents Windows XP from Starting http://support.microsoft.com/default.aspx?scid=kb;en-us;Q307545

Thanks mollydaisy and stevenlewis for your help. To answer Stevenlewis' question: safe mode does not work, I got the same message. I went through part one of the solution suggested in microsoft knowledge base article Q307545. Then for part two you need to boot into safe mode to get access to the hidden system Volume Information folder, but there I get the message Windows XP could not start because the following file is missing or corrupt: \WINDOWS\drivers\ntfs.sys Using the listsvc command I found out that ntfs is disabled. I tried booting into the last working configuration (not sure this is the exact wording of the boot option, but you know what I mean), but there I got: C000021a (fatal system error). The session manager initialization system process terminated unexpectedly with a status of 0xc000003a (0x00000000, 0x00000000) According to microsoft knowledge base article Q316503 this occurs when you have GoBack present in the boot sector. The suggested solution is to disable GoBack at the GoBack start-up screen. However, this screen doesn't appear any more and when I check with listsvc I do not recognise any service that could be related to GoBack.