Windows 7: The group policy client service failed the logon

Hello everyone !
Im using win 7 professional x64!
i was stupid deleted some files like ( ntuser.dat ... ) in C:\User\Username folder
And now , i can not log in to my desktop screen.
I took most 7hrs to searched and tried tried tried , but i did not work.
1. I can not create New Profile when logged into "safe mode"
2. I do not have any restore points create.
3. I purchased window 7 by online and just download and upgraded from win XP , so i can not repair by that way.
How do i do now , so regret when deleted those files.
How can i get it back ? Can i download or copy those files from another PC?
Please help me this step by step please ! thank you everyone.

Boot into safe mode, and enable the hidden administrator account ... then reboot and logon using the administrator account and create a new user account ...

Built-in Administrator Account - Enable or Disable

Thanks Tews for helping ! but... it did not work
i can enable administrator account , but i can not create any new profile or something like that.
The search box which " search programmes and files " in start menu does not work too ... can not search anything there
I just can do are :
+ Change your password
+ Remove Your password
+ Change Your Profile

and can not do are ( with a security logo on front )
+ Manager another account
+ Change User account control setting

How can i do ? can you help me please ! thanks again

Did you create a bootable DVD from the windows 7 download file?? If so, you may need to do a clean install of the OS..

did not you joke? i have many installed software and licensed ... i think i lost those key to active again...

Not to worry.. download BelarcAdvisor ... it will retrieve your product key...

BelarcAdvisor

1 more thing ^^ ! i was using firefox and saved many of favorite links , how can i back up or get all of them back?
I did not install a cleannnnn window yet !

Backing up and restoring bookmarks in Firefox