Demonbael.. what that usually means is there is no recognized bootable media found- that is to say the harddrive doesn't have a useable bootloader, the CD drive and floppy drive neither have a workable OS on them either. Usually the final boot option is over the network (not as used any more as it used to be- but can be very handy.) Hence it goes looking for DHCP...
When it does a POST, do you see it detect your drives?
If you use a bootable CD, what happens? Can you see the HD from there?
Just a few starting suggestions- please let us know what you find.