This article explains how to configure multiple PCAP or IR monitors in Windows 7 or newer

If all monitors are either PCAP or IR touch screens, they run natively off of HID, therefore, Windows will detect them and will not require an Elo touch driver to be installed.

1. Connect the power, video, and touch cables to the PCAP or IR monitors.

2. Navigate to the Windows Control Panel.

3. Go to Tablet PC Settings (if you do not see Tablet PC Settings, make sure your view in the control panel is set to Large or Small Icons and NOT Category View).

4. In the Configure section, touch the Setup button.

5. The screen will turn white explaining to touch the screen to identify it as a touch screen, touch it, it may require a couple of touches.

6. Once finished with the first screen it will then continue to the second screen, repeat the steps above, touching the screen to allow Windows to identify it as a touch screen.

7. Both screens should now be working as expected.