Have you had any success resolving this Terminal Services pass-through issue? Here are some comments:
1) iLO Advanced license is required for TS pass-through.
>>>Note that full client Terminal Services does not need to be licensed for the OS. The mode used by iLO is for remote management supporting max 2 connections.
2) Check that iLO is configured with pass-through Enabled or Automatic. Start with Enabled if you are troubleshooting. This allows you to manually activate it from the Remote Console window.
3) Check that the iLO driver is installed on the host OS. This is called the "HP iLO Management Channel Interface Driver" under device manager/Multifunction devices.
4) Check that the Terminal Services passthrough service is installed on the host OS. This is titled "HP iLO Passthrough Service" under device manager/services.
5) Check that the terminal services client is available on your client system. Hit Start/Run then enter "mstsc" If this does not start the "Remote Desktop Connection" client then iLO might not be able to locate the program.
6) If all of the above are working properly, attempt to restart the service from step (4). Then log into iLO, launch remote console, then hit the "TrmSvcs" button to start the terminal services client.
Let me know how this goes for you, and any questions you encounter along the way.