Enable Processor Compatibility For Legacy OSs in WS2012 Hyper-V

I read on a Windows magazine website today (Monday 12th, November 2012) that the ability to run legacy operating systems, such as Windows NT 4.0 Server or Windows 2000 Server, was removed from Windows Server 2012 Hyper-V.  I would have commented but the publisher wanted me to register.  This feature was removed from the GUI, but it was not removed from Hyper-V.

Note: Neither Windows NT 4.0 Server or Windows 2000 are supported by Microsoft, although you might want to run really old applications in VMs because you can’t get hardware for them.

You can run the following to see the processor compatibility of a particular VM for legacy operating systems using PowerShell (where VM01 is the VM in question):

PS C:> Get-VMProcessor VM01 | fl CompatibilityForOlderOperatingSystemsEnabled

CompatibilityForOlderOperatingSystemsEnabled : True

You used to configure this setting in the processor settings of a VM.  Now you can configure it as follows:

Set-VMProcessor VM01 -CompatibilityForOlderOperatingSystemsEnabled $true

You can turn it off again by running:

Set-VMProcessor VM01 -CompatibilityForOlderOperatingSystemsEnabled $false

Note that enabling this setting requires that the VM be turned off.

This information has been brought to you by Windows Server 2012 Hyper-V Installation and Configuration Guide (available on pre-order on Amazon):


End Of Life Coming Soon

Folks, this summer the following products will be end of life, i.e. no support of any kind for the following products:

  • XP SP2 – upgrade to a newer service pack
  • Vista RTM – upgrade to a newer service pack
  • Windows 2000 – upgrade to Windows XP SP3 or later, Windows Vista SP1 or later, or Windows 7
  • Windows Sever 2000 – upgrade to Windows Server 2003/2003 R2/2008 or migrate to Windows Server 2008 R2.

Go to the Microsoft product life cycle site for precise details.

For the server replacement, I’d strongly consider you look at moving to an x64 server operating system.  Making the jump now will ease future upgrades.  A few notes:

  • Microsoft hates upgrades because they are messy.  Problems are inherited/created.
  • You cannot upgrade from x86 to x64 or vice versa.
  • You cannot upgrade from a full installation to a core installation.
  • You need the correct licensing for the server and the CAL’s.
  • Check application compatibility.
  • Test, test, test and verify with application/hardware vendors before making changes.