boot your computer in safe mode with command prompt and type the following command to enable registry editor:-
reg delete HKCU\software\microsoft\windows\currentversion\policies\system /v "DisableRegistryTools"
and run HKLM\software\microsoft\windows\currentversion\policies\system /v "DisableRegistryTools"
After that your registry editor is enabled
click on run and type regedit
then follow the following path :-
on the right side delete the entries which contain 'Brontok' and 'Tok-' words.
After that restart your system
open registry editor and follow the path to enable folder option in tools menu
delete this entry and restart your system
and search *.exe files in all drives (search in hidden files also)
remove all files which are display likes as folder icon.
Your computer is absolutely free from brontok worm