Graphics card and onboard video wont post?

my hard drive just recently died but the weird thing to me is that my graphics card and onboard video will not post. my computer powers on and lights up, the proccessor fan starts up n stuff, even the graphics card fan spins(msi 4890). will a computer post without a hardrive?|||Yes is should post with out a drive and then just ask for bootable media. Why would you want to if you don't have a drive in?