Is web testing on Windows Server edition the same as Windows Desktop edition?

Yes. The license agreements of Windows Desktop editions (XP, 7, 8 and 8.1) do not allow us to provide remote access to our customers. Therefore, we use Windows Server editions with Desktop Experience, and use the versions of Internet Explorer made for Windows Desktop editions on those OSes.
For Windows 10, we use Windows 10 Professional which is a Desktop edition.

Please refer to the following table to check which Windows Server edition maps to which Desktop edition.

Server edition	Desktop edition
Windows Server 2003	Windows XP
Windows Server 2008 R2	Windows 7
Windows Server 2012	Windows 8
Windows Server 2012 R2	Windows 8.1

Since Windows Vista and Windows 7 are identical with respect to cross-browser testing, we support only Windows 7.