Follow these instructions below:
1. Since you tried Safe Mode and Last Known Good Configuration without success then boot from a Windows XP CD. 2. When you boot from the CD do you see an option that says Press
R to boot into the recovery console? If you see that option press
R.
3. Once you boot into the recovery console it will ask you which Windows installation you wish to log into.
4. Press
1 and hit enter.
5. Next type the administrator password. If you don't have a password then leave it blank otherwise type it in and hit enter.
6. Next type the following commands and hit enter after each one.
fixboot
fixmbr
chkdsk /r
You may be asked to confirm an action after typing in the commands. Type
Y to confirm the action if you are asked. After check disk has finished checking your harddrive type
exit to quit setup. Hopefully the computer will now boot.
7. If the system still doesn't boot then power off the machine, open the case up and take out the harddrive. If you have another computer hook up the harddrive as a slave drive where you can copy all the important data off the slaved drive onto another harddrive.
8. If you would rather not hook up the harddrive as a slave drive then try
Performing a Repair Installation of Windows XP.
Let me know if you can get the computer to boot after performing the above steps. 