SFC found files it could not repair again, logs attached. The Windows Features window now shows all the options again, but I have not checked if they work. Media Features shows off, which is how I last left it.
Alright. I tested turning features on and off and all worked except Media Features, which gave "An error has occurred. Not all of the features were successfully changed.". I'm okay with that one feature set not working, so thank you so much for your help.
There are still remnants of the old WMP from Windows Vista which may cause that behavior.
I will mark this thread as solved.
Follow the instructions below to cleanup the tools and logfiles used in this thread.
Rename the file FRST64.exe to uninstall.exe and run it. This will remove all files and folders created by FRST and the tool itself.
Reboot the machine to complete.
You may remove all other tools and log files.
