ESXi

Based on the compatibility page from VMware, I can see that Windows Server 2008 R2 is supported but when I configure the "Guest operating system" I see the OS being listed as: "Microsoft Windows Server 2008 R2 (64-bit) (experimental). Is this correct? We're not 4.0.0 Build 208167 which I believe is the latest build. Thanks.

As of VMware vSphere Update 1, 2008 R2 is supported. You must update not only your vCenter server but also all of your hosts.

U1 supports W2K8R2

http://www.vmware.com/support/vsphere4/doc/vsp_esx40_u1_rel_notes.html

Windows 7 and Windows 2008 R2 support –This release adds support for 32-bit and 64-bit versions of Windows 7 as well as 64-bit Windows 2008 R2 as guest OS platforms

You are running vCenter? If so, what version?

We're running vCenter 4.0.0 162856. Thanks.

update your vCenter to U1, that will probably fix the issue

Perfect! Thanks Troy.

Terence