I just recently helped out with a very similar support case. The problem was that while VJoy installed successfully, ISE could not (for reasons unknown) automatically create a VJoy-device through vJoyConfig. I solved the problem by manually creating a vJoy device and pointing ISE to it.
Follow these instructions step by step:
1. Launch “Configure vJoy” (vJoyConf.exe).
2. Make sure the “Enable vJoy” checkbox in the bottom left corner is checked (if it’s present).
3. Click “Reset all”.
4. Select the number 2 tab (the number of the tab must match the value of the “/d”-switch in step 10).
5. Click “Add Device”.
6. Uncheck all checkboxes under “Axes” except X and Y.
7. Set “Number of Buttons” to 0.
8. Click “Apply”.
9. Close the application.
10. Press Win+R, type “REG ADD HKEY_CURRENT_USER\SOFTWARE\Tobii\InfiniteScreen /v vJoyDeviceNumber /t REG_SZ /d 2” and press Enter (press “y” and Enter if “Value vJoyDeviceNumber exists, overwrite(Yes/No)?” shows up).
11. Launch ISE.
12. Report the outcome in this thread :).
Good luck!