A friend of mine, Tom Fagerland, tried to install Exchange 2007 SP1 on a Windows 2008 Server R2 box today, and somehow it wouldn’t work. I tried to figure out what the problem was, but after a couple of Google searches we soon realized the problem; there is currently no support for Exchange 2007 SP1 in Windows Server 2008 R2 (beta), and an install will probably fail with the error “File not found”. We need to wait for Exchange 2007 SP2 for full support with Server 2008 R2, but there is however a workaround if you want to test it. Read more about it at the Microsoft Forums or a similar thread. No guarantees it will work, though.