I'm a major newbie, but our phone system is running asterisk. About a year ago, the motherboard/CPU failed, and i was able to just swap the hard drive into an old computer we had and it worked. (I know i got lucky).

Well, it's happened again, and I took the Hard drive from the old system and put it into a new one.

Now when it boots, i have the errors

Red hat nash version 4.2.15 starting
mkrootdev: label /1 not found
mount: error 2 mounting ext3
ERROR opening /dev/console!!!!: 2
Kernel panic - not syncing: Attempted to kill init!

I can get the system booted up on the old system, but hardware issue prevent me from using that system.
Any help you could offer would be tremendous.

Is the new system substantially newer hardware? What linux kernel are you running on the old system (hint: uname -a)? What is the hardware of the old system and what is the new system (i.e. make/model of motherboard)?

My best guess is that there is no driver in the old linux kernel for the hard disk controller (i.e. the motherboard chipset) on the new system. If there's no driver present, the old linux install doesn't know what to do with a hard disk.