Windows 7 logon access denied

Hi guys, I hope somebody can help me with this problem. And the problem is I cannot login to my windows 7. On the startup, when it comes to the logon screen I receive message "the group policy client service failed the logon. access is denied". I tried to boot in safe mode, in mode with cmd, no success. I tried to create new profile in cmd, but I cannot assign this profile to local group. The only thing I want to do is to log into windows somehow to copy my documents to external hard disc, so I can perform format disc. I hope someone has the sollution..thanks

thank you Rich,
but the problem is that this occured on my laptop and I don't have appropriate tools to take the hd out. I thought maybe there is some way I could enter windows and copy my documents..