This Will Take Like 15-20 mins.
Go To Your Wow Folder And Go To Data Folder.The Are 2 Files Named "Patch.MPQ" and "patch-2.MPQ".Delete Those 2 Files.After You Delete those Go To Your WoW Folder Again And Open Repair And Click on "Reset and Check Files".Wait until The Repair Thing is Finish.After That You Go To Your Wow Folder again And Open Launcher.Will Begin To Update Patches Again.I think will Begin With 2.0.0,after that with 2.2.0,2.3.0,2.4.0,2.4.2 [DONT LET IT GO TO 2.4.3] When You See That His Beginning To update 2.4.3 CLOSE the Window.
I hope This "Tutorial" helps.