I don't have access to one of these units. I see looking at the specs that there are both USB 3.0 and USB 2.0 connections on the rear of the server, try using the USB 2.0 ports.
After typing the above I noticed in the support matrix, 2008R2 is not supported on that server http://h17007.www1.hpe.com/us/en/enterprise/servers/supportmatrix/windows.aspx
No support by private messages. Please ask the forum!
