The Intel® HD Graphics 4000 video controller included in the processor you have; has been tested with World of Warcraft: Mists of Pandaria and it has been determined as playable.
For the list of tested games, go here:
Please provide us the dxdiag generated in your system in order to have more information on the system that you are using. To get this report, you can go to the start menu and run dxdiag, then click on save this information and copy paste here the contents on the file that you will create.
Those types of error messages are usually generated when there is a corrupted game file if my memory of playing WoW serves me right. However, if we're going to determine if it's an issue you have with the HD 4000, we'll need a copy of your dxdiag. Can you post one so we can look please? (Start -> Run -> dxdiag -> Save All Information).