id summary reporter owner description type status component version resolution keywords cc guest host 16196 Cannot start VMs in Windows 10 x64 dburke3 "After initial install of virtual box I was able to create and run a red hat VM. After a restart of the PC, I was not able to start the red hat VM, nor any others (I tried creating Ubuntu and Win7 VMs as a test). When attempting to start one, the following error occurs: ""supR3HardenedDllNotificationCallback: NtCreateFile failed on 'C:\windows\System32\umppc4702.dll' / '\??\C:windows/System32\umppc4702.dll': 0xc0000034 (rc=-225) Please try reinstalling Virtual Box. where: supR3HardenedWinCheckChild what: 5 VERR-INTERNAL_ERROR (-225) - Internal error - this should never happen."" Reinstalling virtual box/restarting the PC had no impact. Running as administrator had no impact. Both 5.1.8 and the 5.1.9 test build exhibit the same issue. Host is Windows 10 Enterprise 64 bit. " defect closed VM control VirtualBox 5.1.8 obsolete all Windows