ok before doing what i whote above , try to do that
Start Menu => Programs => Accessories => right click on "command prompt" => "run as administrator"
in the black windows type (or paste)
net stop wuauserv (then [enter])
ren %windir%\Softwaredistribution %Windir%\SoftwareDistribution.bak (then [enter])
net start wuauserv (then [enter])
close the command prompt , reboot your machine and try again your updates