It could be that the hard drive "took a hit" from the unplugging of the computer, and has bad sectors.
In my opinion, a good start would be to boot from your Windows XP CD and going to the Recovery Console (press R on the "Welcome To Setup" screen). The Recovery Console is basically a command prompt interface with tools to recover your Windows XP. In the Recovery Console type "chkdsk /r" (without the quotes). This will check your hard drive for errors and fix them, if possible. When it is done (may take a while), type "exit" and the computer will restart. See if the error returns after that.
If chkdsk finishes very quickly, or doesn't reach 100%, it may be a sign of hard drive failure.
A word of caution: if the hard drive is already singing its "swan song", running chkdsk may cause data loss. It never happened to me, but I know that there is a chance.
In my opinion, a good start would be to boot from your Windows XP CD and going to the Recovery Console (press R on the "Welcome To Setup" screen). The Recovery Console is basically a command prompt interface with tools to recover your Windows XP. In the Recovery Console type "chkdsk /r" (without the quotes). This will check your hard drive for errors and fix them, if possible. When it is done (may take a while), type "exit" and the computer will restart. See if the error returns after that.
If chkdsk finishes very quickly, or doesn't reach 100%, it may be a sign of hard drive failure.
A word of caution: if the hard drive is already singing its "swan song", running chkdsk may cause data loss. It never happened to me, but I know that there is a chance.