I you are using the ADK Beta and MDT 2012 to install Windows 7 you will get the following error:

The procedure entry point ??0WString2@@QAE@XZ could not be located in the dynamic link library X:\windows\system32\wbem\fastprox.dll.

Links:

http://social.technet.microsoft.com/Forums/en-US/mdt/thread/a9918617-200a-42b3-af80-bb27ddccc8fe

If you click OK twice you will get past it and the install will continue.

The problem is due to the fact that ADK disables short file names

The supported solution is of course to use Waik instead.

Link:

http://social.technet.microsoft.com/Forums/en-US/mdt/thread/a9918617-200a-42b3-af80-bb27ddccc8fe