Disk Boot Failure, Insert System Disk error

[Tret]

Well, I just turned on one of the computers today, and everything was starting up fine, up until the verifying dmi pool date appears then it says Boot from CD:
Disk Boot Failure, Insert System Disk and Press Enter.
I'm running windows xp pro. I have a xp disc lying around here but I don't have the cd key on hand since I can't find the paper and can't access my computer to see it.
System: Windows XP PRO
Amd FX 55
2x 74 Gig Raptors
2x Seagate Drives
2gb PC 3200 OCZ titanium ram
Video Card: 7800 GTX

I checked bios and the computer reconizes everything.
I think this happened once before a long time ago and I just restarted and it worked fine. Can it be that I need a new Motherboard Battery?
I tried disconnecting the power source and let the computer completely turn off restarted wouldn't work
I made sure that all my cables are connected correctly.

 

[Mr Bob]

You're not the only one: http://www.google.com/search?q=Disk+Boo...e=utf-8&oe=utf-8&rls=org.mozilla:en-USfficial&client=firefox-a

 

[Tret]

I resetted the cmos battery and it works again.