Installed and started game, now I have no HDMI signal

[Tim Luke Picard]

So, I just installed this game on my Windows 8 machine... When I went to start the game, steam began to install a DirectX redistributable package, which was fine... I went away for a minute, and when I came back my TV said that there was no signal from the source.

I switched my PC off. Switched it back on. BIOS splash screen and everything was as normal, even got the Win8 loading splash screen... then... nothing. Again.

I have no idea what's gone wrong, and I have no idea how to get in to safe mode with Win8 in this case because AFAIK they messed around with it so that if you want safe mode you gotta specify in the OS before you shutdown... you can't just mash F8 anymore.

Any help?