Nick

Control Panel says 8.1 was installed on 16/3/07, I was using 8.5 beta after
that, then was using 8.5 final perfectly happily till today when it all went
wrong.

I tried that command rundll32 setupapi,InstallHinfSection BLC.Remove
128 %SystemRoot%\INF\msmsgs.inf

but it said "Error. Installation Failed"