Disk Boot Failure

-----Original Message-----
I hope I am not out of luck on this one... I was running
Windows XP Pro for about six months with no problems at
all. One night I was running a fairly long query and
submitted it, then went to bed as it ran all night.

When I awoke in the morning, I had this error on my
computer
"Disk Boot Failu Insert System Disk and Press Enter"

Is there anything that can be done... I've exhausted all
that I know to try but to no avail... HELP!!!
.I have had this error message on start up its mainly
intermitant but sometimes wont stop happening and Ive
cured it temporarly by opening up the computer and
unplugging the hard drive and then just plugging it in
again I now leave the side panel off this does not cure it
but seems to keep it running Im now trying to swap
everything to a second hard drive and have other problems
to.