A. The WoW64 component is named ServerCore-WOW64. To install it, use the standard ocsetup method:

Start /w ocsetup ServerCore-WOW64

To uninstall, use

Start /w ocsetup ServerCore-WOW64 /uninstall

Note that this installs/removes the core WoW64 environment, and you need to reboot after changing this. There are also additional WoW64 packages for the various Windows Server 2008 R2 roles to enable 32-bit application support in those roles:

  • Failover Clustering—FailoverCluster-Core-WOW64
  • PowerShell—MicrosoftWindowsPowerShell-WOW64
  • .NET 2—NetFx2-ServerCore-WOW64
  • .NET 3—NetFx3-ServerCore-WOW64
  • Printing—Printing-ServerCore-Role-WOW64
  • Server Core IME—ServerCore-EA-IME-WOW64
  • SUA—SUACore-WOW64

Before installing these components, you must first install the native 64-bit role/feature that this augments with 32-bit compatibility. For example, before installing NetFX3-ServerCore-WOW64, you need to have installed NetFX3-ServerCore.

You won't be told by an application install or application execution that you are missing WoW64 if you need it. Instead, you'll see more generic errors such as "Error 1719: The Windows Installer Service could not be accessed" during a 32-bit application installation, or "The system cannot execute the specified program" id you're trying to run a 32-bit program.

Related Reading:

Check out hundreds more useful Q&As like this in John Savill's FAQ for Windows. Also, watch instructional videos made by John at ITTV.net.