Guess you have probably fixed your issues by now, or have given up and done a refresh /restore.
I've had the issue as well - running ZoneAlarm, which comes with a ZA PC tune up, presumably some type of registry cleaner.
Trying sfc or dism after running tune up gives a variety of 0x800 codes, the usual one being the one ending with 'no operation was performed'.
Unresponsive to SCFix or use of safe mode, but oddly enough will do in 'clean boot' mode.
That's msconfig - services - hide ms services (tick) - followed by 'disable all' (tick) - apply - ok - computer needs to be restarted (tick).
After restart in sequence:
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
dism /online /Cleanup-Image /StartComponentCleanup
dism /online /Cleanup-Image /RestoreHealth.
I suppose what this means is that whatever is blocking dism from working ceases to do so when only windows processes are active.
Anyway may be worth a try for someone, as reinstalling all programs is a definite pita.
johnny