I was getting a cycle of "Windows did not start properly" messages and Safe Mode and Last Known Good Configuration were not working so I tried to boot from the Recovery Disk to run CHKDSK etc. When the recovery disk tries to boot I am getting STOP 0x0000007B blue screen of death. I have tried several recovery disks now. I did manage to run a diagnostic check from the boot menu to check CPU etc. and that all passed.