Host: Windows 8.1 Update. VMs can see only Single CPU

[TomCemerka]

Hello,

I came across an issue with VirtualBox post Host upgrade from Windows 8.1 to Windows 8.1 Update.

Host: Windows 8.1 Update
Guest Windows 7
VirtualBox: 4.3.10 r93012

Only single CPU available for Guest systems: tested with Win7 and Ubuntu Guests

Existing VM's fail to launch with error:
Error that V-TX is not available:
Result Code:
E_FAIL (0x80004005)
Component:
Console
Interface:
IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}

Newly build VMs using hosts Windows 8.1 Update only can have single CPU and 32-bit.

[mpack]

Turn off the Hyper-v service in the host OS.

Further information along these lines can be had by reading the Win 8.1 sticky near the top of this forum.

[TomCemerka]

Turn off the Hyper-v service in the host OS.

Further information along these lines can be had by reading the Win 8.1 sticky near the top of this forum.

Thank you so much. This has done it.