I did a system restore to a point three days ago - that worked OK.I then did a System Restore Undo to revert my system backUpon loading my desktop, it said that the System Restore had failed and there was a stop message (which I failed to note).I re-booted, and the System Repair window came up and said that the system would not start and it would try to repair it.During the repair process it asked if I would like to do a system restore to as point where the system worked. I said yes.After about 20 mins of disk activity it said it was unable to repair my system, and it turned the computer off.I re-booted and the system started normallyand it appears that the Undo that originally failed has somehow worked.W7100 RC, AVG free.