The Windows Experience Index (WEI) provides a benchmark of the major components in your computer.
I recently tried to run WEI on a clean install of Windows 8 because I had just installed my first Solid State Drive (SSD) and was curious to see how it compared to a regular Hard Drive.
Unfortunately I ran into the following error: Could not measure video playback performance.
The video files that WEI uses to measure playback are in the C:\WINDOWS\Performance\WinSAT folder.
The problem for me was that Windows Media Player (WMP) had not been run and set-up yet.
Once I had run WMP I made sure that the video files in the WinSAT folder all opened with WMP – and after this WEI completed without issue.
For the record I did not have any codecs installed on my system – but I did have VLC Player installed. Updating my video drivers did not make any difference to whether WEI completed or not on my computer – your mileage may vary!
If this does not fix your issue I recommend that you look here.