MSDN 上的好像在这里。
https://msdn.microsoft.com/en-us/subscriptions/downloads/default.aspx?PV=36%3a351&lc=1033#searchTerm=&ProductFamilyId=351&Languages=en&Architectures=x64&ProductFamilyIds=351&PageSize=10&PageIndex=1&FileId=0
Windows Server 2008 R2 评估版
http://www.microsoft.com/zh-cn/download/details.aspx?id=11093