I recently ran into an issue when installing my first Windows Server 2008 R2 virtual machine.  The VM would hang/freeze randomly when used through the VMware vCenter Client’s console.  It turns out this is a known issue (see this VMware KB Article) with the SVGA driver that is installed as part of the default installation of VMware Tools.  While the article does not explain why you should disable the SVGA driver, it’s advice is correct if you want to avoid problems in your guest VM.  To correct my problem, I removed the SVGA driver from the Windows Device Manager and rebooted.  If you are having problems removing the SVGA driver before the VM hangs, use Remote Desktop to access the guest machine to perform the driver uninstall.  I have not observed hanging/freezing in the VM since removing the SVGA driver from my Windows 2008 R2 guest.  Note that this same issue is present in Windows 7.