K KeithAdv Member Joined Mar 21, 2014 Posts 6 Mar 21, 2014 #1 I think it all started when my Win 7 system drive started to go bad. The first thing I noticed (in addition to the disk errors) was that I no longer had audio and midi. I have a specialized audio driver/interface that is still working but everything else is gone. I'm running 64-bit professional on a home built machine. The Windows Audio Endpoint Builder service will not start, which keeps the Windows Audio service from starting. If I try to start the Endpoint Builder manually through services.msc, I get "Error 5: Access is denied." sfc /scannow reveals that MMDevAPI.dll.mui, MMDevAPI.dll, and AudioSes.dll have problems, but it can't fix them. I'm assuming that's why the Endpoint Builder service won't start? Sadly, I have to confess that I may have made things worse. I grabbed the above two dlls off a web site and tried to do some voodoo Take Ownership to copy them over the existing files that appear to be damaged. I was at least partially successful but I realize now that I may have simply created more problems. I have restored ownership to TrustedInstaller, as far as I know. But then again that also means that I restored ownership to illegitimate files. I've tried uninstalling and reinstalling my various audio drivers to see if the files get replaced but nothing doing. This one is way beyond my meager abilities. Any advice/next steps? Thanks for all consideration!