The other night I updated my iTunes to the latest version (through Software Update) when I came to turn on my computer I was greeted with the dreaded white screen of death.

I use an early 2008 iMac 24".

I've tried the basic things, unplugging/turning off accessories, trying to boot from the install disk, reseting pram, etc, etc.

Still no luck and no change what-so-ever.

All I've been able to ascertain that my keyboard still works (by ejecting).

I should point out that I did recently replace my Hard drive with a Western Digital Black 500GB (though the computer is well out of warrenty) and I'm a little concerned that the problem could be the screen.