If you don't have a tablet-based PC, you should disable the Windows Tablet PC components and services. These components may interfere with the Wacom Cintiq driver software.
Open the control panel. Select Programs and Features, then Turn Windows features on or off.
Scroll down the list. Deselect Tablet PC Components. Click OK.
(Note: they may be disabled already.)
If prompted to restart the computer, do so now.
Disable the Tablet PC Input Service
Next, stop and disable the Tablet PC Input Service. This service may interfere with the Wacom Cintiq driver software.
In the start menu, type services and hit enter. The service manager should appear. (If not, hit the Windows Key+R combo, which brings up the "Run" dialog and type services.msc in the Open box, and hit the OK button). Scroll down to the Tablet PC Input Service. If it is running, click the Stop button, and then select Disabled from the Startup type dropdown list. Click the OK button.
There should be no need to restart the computer.