Fixing Windows 2012R2 Hyper-V Role Failing At 99 Percent

installing the Hyper-V Role is straightforward on a new system, I have seen couple of scenarios where the Hyper-V role will fail on installation. Scenario conditions are outlined below:

  • Fresh install of Windows 2012R2 Server.
  • All Windows Updates applied then rebooted.
  • Post reboot, Hyper-V Role was installed.
  • Rebooted machine to finalize installation of role
  • Machine begins applying, gets to 99%, then fails to install the Hyper-V role. Windows performs rollback.

Resetting Windows Registry Files To Fix Hyper-V Role

The fix that worked for us was to open up a Command Prompt and select Run As Administrator (or create a batch file and run as an administrator) with the following text.

Resetting Windows Registry Files to Fix Hyper-V Role
sc config winmgmt start= disabled
net stop winmgmt /y
%systemdrive%
cd %windir%\system32\wbem
for /f %s in ('dir /b *.dll') do regsvr32 /s %s
regsvr32 %windir%\system32\tscfgwmi.dll wmiprvse /regserver net start winmgmt for /f %s in ('dir /b *.mof *.mfl') do mofcomp %s cd C:\Windows\System32\wbem\AutoRecover
for /f %s in ('dir /b *.mof *.mfl') do mofcomp %s

After the commands above have been executed, the following should now run successfully:

  • Install the Hyper-V Role
  • Reboot the machine
  • Hyper-V will now successfully apply