"Interactive logon process initialization has failed!" after reboot.

I got this error “Interactive logon process initialization has failed. Please consult the event log for more details”
atfer I installed Avast7 on my father’s laptop(Windows 7) because his laptop had no any antivirus software yet.

I can not even go into Safe Mode. I still got this error. What’s should I do?

Everything was working properly until I installed this software and reboot.

Why this serious problem occurred?

Any help would be appreciated.

Thanks!

welcome to the forum. This might help you out.

http://forums.techarena.in/operating-systems/1121072.htm.

good luck