Hi,
This issue is not hardware or software but could be some configuration issue.
Use notepad to edit the .rdp file and add the following:
enablecredsspsupport:i:0
See the below links:
http://social.technet.microsoft.com/Forums/windowsserver/en-US/b8e58d83-3178-4490-b4f4-1c6e5542c39a/rdp-slow-initial-connection
http://technet.microsoft.com/en-us/library/ff393716(v=WS.10).aspx
Thank You!
I am a HP employee.