Verify that the user has permission to initiate Remote Control. Administrators, by default, can use Remote Control with other users' sessions. Users do not have this right. To give specific rights for groups other than Administrators:
Start the Terminal Services Configuration tool.
Double-click the connection you want to modify.
Click the Permissions tab.
Click Advanced, and then click Add.
Specify the user or group you want to add so the user or group can use Remote Control.
After adding the user or group, the Permission Entry dialog box appears. Click to select the Allow column for Remote Control.