Windows Update error 0x80070003

Click Start (Press “Windows Key + Q” to open Charms Bar.)

Type: cmd

Right click on cmd in start menu and select 'Run as Administrator'

Type: net stop wuauserv

Hit Enter

Type: ren c:\windows\SoftwareDistribution softwaredistribution.old

Hit Enter

Type: net start wuauserv

Hit Enter

Type: exit

Hit Enter

Attempt to download updates .

Source: http://answers.microsoft.com/en-us/windows/forum/windows_8-windows_update/windows-update-error-0x80070003/8badf153-81d8-4d9c-a864-0fa214b8cdc3

-- Cheers !!!