TV Decoder HD HDMI PC without HDMI

I have the HDTV decoder box with the New / SFR with an HDMI output or not having the TV I thought I plug it into my PC but unfortunately it has no video input and my screen has one VGA input.
How can I get the video signal (HDMI) in my PC for watching TV on my screen?

Thanks

There's probably an adapter, but loss of quality. HDMI is digital and VGA analog.

The output of your decoder can be plugged into a screen and not on a PC. The HDMI output supports a screen.