I'm having a real issue at the moment. My computer crashed earlier today, and now whenever I turn it on, I am basically blind (black screen) until the Windows 7 login page comes up. When I first logged back in there was a massive lag in startup, and AVAST! stopped working.
Has anyone got any idea at all? Quite worrying as I can't even get into the BIOS!
How many gpu's are you running? Not sure about the BIOS on your motherboard but some allow you to chose which pci-e slot to use as first output. If yours is set to a slot which your gpu is not plugged into, you will not see any output until the drivers load for the video card which is basically the windows log in screen. I would not worry too much if everything works and you are just missing the POST/splash screen then it is probably something silly like that. If you are using more than one video card then plug your monitor into the second card and see if you get your splash screen back. Either way, It would help if you also listed which gpu you have and which slot in the motherboard it is plugged into and if you have more than one gpu.
I am curious what caused your system to crash like that. Were you overclocking? A 'massive' lag in startup usually indicates a problem that the BIOS is trying to correct which usually ends up in an automatic reset to default settings so the system can boot. Anyone who overclocks as a hobby is quite familiar with that. What were you doing when it crashed?