I just updated to the latest Intel Graphics Driver (Version 188.8.131.5265 from 07.05.2013) and found that my test program no longer worked (calling the Media SDK with hardware encoding on Windows 7 - 64bit with Intel HD 4000).
Upon investigation, I found that the dispatcher registry keys (HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Intel\MediaSDK\Dispatch) were still pointing to an old version of the media sdk.
Between the last few versions of the driver, on a 64 bit system, the location of the media sdk has moved from:
C:\Program Files (x86)\Intel\Media SDK
C:\Program Files\Intel\Media SDK
This applies to the 64-bit and the 32-bit versions of the dlls (libmfxhw32.dll / libmfxhw64.dll). They are now both located in C:\Program Files, while they used to be in C:\Program Files (x86).
Uninstalling the graphics driver completely through the control panel and reinstalling it does not update the registry keys, and updating the driver will not delete the old media sdk version. The only fix I found was to manually delete the dispatch registry keys and then reinstall the display driver. Otherwise, the dispatcher would not find the latest version of lbmfxhw__.dll, and still point to the older version.
Please, Intel Guys, this could create many support issues for end users of Media-SDK-enabled apps. Please fix the display driver installer so that it automatically updates the dispatch registry keys to point to the latest version. I cannot ask my end users to manually delete registry keys.
Yes, this issue with the driver for Intel HD Graphics 2500/4000+ driver on 64-bit OS was discovered and is fixed in the next driver release that should be available very soon. We are sorry for the inconvenience this release caused and appreciate your understanding.
Please continue to report any issues you see.