If your monitor (and/or graphics card) is not EDID compliant then it will not return the information, so nothing will be displayed.

To confirm this you can check the registry information manually.

Warning! Mucking about in the registry can really bugger your operating system up - only do this if you fully understand the implications!

Ok, start regedit and navigate to registry key "HKLM\SYSTEM\CurrentControlSet\Enum\Display"

In this key you will find a number of subkeys, which represent graphics cards, drivers, monitors and other display devices.
  • Look through each subkey, and you will see a key with a hexadecimal garbage string - possibly an internal resource id, but don't quote me on that.
  • Look in this key for a DeviceID. If the DeviceID string starts with "Monitor\" then the entry is a monitor. "Class" is also set to Monitor.
  • Now look for a subkey called "Control". I use this to identfy the active monitor - I have no idea if this is a valid test, but it works for me. If it doesn't have the "Control" subkey the script ignores it.
  • Finally, look in the "Device Parameters" subkey. This should have an entry "EDID", which is the response from the monitor. This is a binary block with the data encoded in it.

The script is an example of parsing this block which may not work for everyone. Specifically I assume that there is only ever a single "garbage" subkey, however this is not necessarily the case.

If you find that the script is not displaying data when it should, post the details and I'll see if we can get it working for you.