How can I verify whether or not Windows Server 2008 R2 has SP1 installed?
Usually Windows shows SPX on the System Information screen - is that the case for Windows Server 2008 R2? Is this a reliable way to verify whether or not SP1 is installed on this machine?
WinKey+R, enter winver It will print Version 6.1 (Compilation 7601: Service Pack 1)
And no, your installation doesn't have SP1 installed (it adds a 3rd line to version section)
The command winver will give you What you need.