Well, first it got stuck at 97% for good 6 hrs. So I rebooted all the 4 office PCs. But it kept getting stuck at 97% so I downloaded msu update files from here. I finally managed to install it on all the PCs and out of the 4, one PC is into BSOD loop. Other 3 PCs booted up fine. So I ran these commands Code: Dism.exe /online /Cleanup-Image /AnalyzeComponentStore Dism.exe /online /Cleanup-Image /StartComponentCleanup StartComponentCleanup failed on all the three PCs with error code 2 because some file was missing. sfc /scannow returned no errors. So I re-installed Windows 10 1607 build from scratch on the 4th BSODing PC and kept it disconnected from internet. Installed KB3189866 from msu file along with servicing stack update and adobe flash. Now even that PC failes on StartComponentCleanup WTF Microsoft? Windows 10 has become this huge Frankenstein monster which even MS themselves cannot tame.