Can you boot the machine into safemode and perhaps perform a system restore?
http://pcsupport.about.com/od/fixthe...-windows-7.htm
http://www.howtogeek.com/howto/11238...ws-7-computer/
http://pcsupport.about.com/od/fixthe...-windows-7.htm
http://www.howtogeek.com/howto/11238...ws-7-computer/