If you get this message when trying to access a XP (or 2000 server) system via remote desktop, try the following …
On the remote system, click Start, then Run, type “secpol.msc”, and press enter.
Navigate to “Local Policies”, then select “User Rights Assignment”.
In the list find “Allow logon through Terminal Services” and make sure that “Administrators” and “Remote Desktop Users” are in the list. If they aren’t, click “Add User or Group”, and add the user. Then click “Apply”.
You should be able to access the system remotely.