Windows 2008 R2 - SP1 (Direct Download Link)

http://technet.microsoft.com/en-us/evalcenter/dd459137.aspx

http://care.dlservice.microsoft.com/dl/download/7/5/E/75EC4E54-5B02-42D6-8879-D8D3A25FBEF7/7601.17514.101119-1850_x64fre_server_eval_en-us-GRMSXEVAL_EN_DVD.iso