If I launch my pc now all lights light up but my monitor says "going to sleep" and then turns off. So no way to boot in safe mode...

And I've not been able to remove Medieval 2 yet as I can't seem to get my pc working...

It gives me the feeling that my pc actually does launch but my monitor doesn't, or that my pc doesn't 'see' my monitor. (There's nothing wrong with my monitor, I tried another one but got same problem)

I suppose you mean with 'connections' that all wires are plugged in correctly? They are.

Thanks for keep helping me I really appreciate it