Posted 13 March 2009 - 10:24 AM
Your symptom is one I have seen several times in the past month and has generally been the result of a Trojan being partially clobbered. The last bit that was left removed all of your permissions so you no longer have permission to log in.
It may be possible (operative being MAY) to correct this issue; but, I have tried for many hours and, even when I got to where I could log in, the O/S was still massively crippled.
Your best bet is to connect the drive to another PC that works, copy off the files you want (pictures, taxes, Quicken, etc) then start from scratch, especially if the CTRL-F11 still works.
Computer dinosaur, servicing PC's since 1976