If you are having issues with remote desktop sessions being really slow and laggy, this can be related to Vista and Windows 7 (Windows Auto Tuning).
The fix that has worked for our testing is the following:
Run a command prompt as an administrator (this requires you to be a local administrator of the machine you are doing this on)
type the following command:
netsh interface tcp set global autotuninglevel=disabled
This should resolve the laggy or slow response in some remote desktop windows, the remote desktop windows will need to be closed and reconnected.
If you ever need to remove this option due to any adverse effects, use the following command to return this setting to default:
netsh interface tcp set global autotuninglevel=normal
How to run a command prompt as an administrator:
Demonstrated in this screenshot, you can access this by clicking on the start menu,
in the search bar typing cmd and then right clicking on the search result as displayed in the screenshot below and clicking run as administrator.