Even though Windows Server 2008 R2 is exclusively a 64-bit operating system, 32-bit applications are supported by enabling the WoW64 optional feature. If this feature is not enabled and you try to run a 32-bit application, the application will fail to execute. The WoW64 execution layer is an optional component that is installed by default on R2 releases after beta1. You can save resources by removing the feature if you are not going to be running 32-bit applications on your Server Core install.
Install the WoW64 Execution Layer using the following command:
dism /online /enable-feature /featurename:ServerCore-WOW64
If your solution has a .NET 32-bit dependency, then also invoke the following sequence:
dism /online /enable-feature /featurename:NetFx2-ServerCore
dism /online /enable-feature /featurename:NetFx2-ServerCore-WOW64
Note: With Windows Server 2008 R2 beta1, WoW64 is an optional feature. This is changing. With Windows Server 2008 R2 RC1, WoW64 will be enabled by default. If you don't want WoW64 enabled, just disable the feature as follows:
dism /online /disable-feature /featurename:ServerCore-WOW64