I strongly think that your Icy Box has a fault, with me it works perfectly with HDMI on the TV as well as now with PC monitor on the MSI Prestige14 inch, think that the fault is not on the PC, ev if you have an ancient operating system on the PC like W2000 or Millennium or so, I have W10. no I really think your box has a fault and you have to have it replaced. Otherwise, here's how I do it, Icy Box connected to the PC, is funnily enough recognised as a sound device, but works perfectly when I now plug in HDMI, even if I restart with HDMI contact, it works, only once the screen was black and I had to cancel and restart. Hope this helps.