S-Video and SCART are older standards, HDMI is a modern one and should work best for connecting TVs and Computers.

If the connection is established and the TV uses the HDMI port as a source, then I'm not sure why it would give an error, could be an issue I'm not aware of or a wrong setting somewhere or something could not work correctly.
Just to be sure:

1. You did change the TV's input to HDMI if it does not do so automatically?
2. When you look at the Windows settings for monitors, you can see the TV, access its settings and did set a dual-diplay mode if it was not set automatically?
3. Which OS are you using anyway?