I am building a new development environment on Windows Server 2008 R2. I have followed the steps outlined on Win2008R2Workstation.com but couldn't get Aero Glass transparency enabled. I finally figured it out and so I thought I'd share it, because I see that many people have this problem.
Getting Aero transparency to work in Windows Server 2008 R2 in VMWare.
By default, 3d acceleration is disabled in VMWare. For some reason this doesn't adversely affect Windows 2008 Server or Windows 7; just Windows Server 2008 R2. The fix is to force VMWare to enable 3d acceleration. TO do so, add the following lines to the VMX file for the virtual machine...
mks.enable3d = TRUE
svga.vramSize = 67108864
I put them at the very bottom. It doesn't matter, because VMWare will rearrange the file to its liking.
Save the file and restart your VM. When it comes up, you should have Aero Glass transparency.