For required patches :
Extract the Patch-M-N-O-U. MPQ archives from your WoW/Data/ folder.
The Patch-U archive contains a WoW. exe, put it in your WoW/ folder. Without this one, we won't be able to play.
For HD patches :
Extract the Patch-HD archive (containing the Patch-A and Patch-B) from your WoW/Data/ folder.
Then download the Patch-Y. MPQ and put it in the same folder.
DON' T RENAME ANY PATCHES!
Make sure there are no patches from other servers in your WoW/Data/ folder. In the end you will have to have the patches:
Patch, Patch-2-3- (A)- (B)-M-N-O-U- (Y).
Patches in brackets are optional patches (HD).
REQUIRED PATCHS' SERVER
PATCHS HD GRAPHICS