Archive for March, 2016

Windows updates on Windows 8.1 almost made my system unbootable

March 15, 2016

I  have an older  (Haswell based) X1 carbon which is running Windows 8.1. I was installing updates on it and after that the system wouldn’t boot and would keep getting to recovery loop. The system is bit lockered. I couldn’t get the system into safe mode or enable debugging. System restore had restore points as I seldom log into my local admin accounts and use mostly my domain  joined account. I tried the startup repair diagnosis and that didn’t find much either. So the system was pretty much unrecoverable. I went and looked at the SRtlogs (attached) and they pointed to a corrupt cng.sys binary. Sure enough it was reduced to 4 kb in size. I tried to patch it with a binary from another 8.1 system but that didn’t help. In the end I ran the sfc tool and that’s when I started seeing issues. Error from the tool:

“Error :There is a system repair pending which requires a reboot to complete. Restart windows and run sfc again”.

I researched the Windows community board which actually led to the diagnosis that there was a pending update which was for whatever reason causing the behavior and found the dism command below. Ran this and rebooted the system came back online.


dism.exe /image:C:\  /cleanup-image /revertpendingactions

The drive above could be D: or another one.  Check your system for the drive which has the Windows, Program Files etc directory to be sure.


If you get stuck in a loop with the message Windows couldn’t update the system… Try F8 to use restore point or try and reeboot before you reach the We cant install the update screen and this will cause recovery to be invoked. Happy fixing…

 I cant imagine non technical savvy user doing this…


Hope this helps!!