Installing SharePoint on Windows Server 2008 R2

You will need to slipstream the install with SP2. Have a look at this post from Jie Li:

https://blogs.msdn.com/opal/archive/2009/05/08/install-moss-2007-wss-3-0-on-windows-server-2008-r2-you-will-need-sp2-slipstream.aspx