have you tried this ......
restart the laptop press F8 it will open to boot the laptop through various process like safe mode , last good known ..... select the last good known option and press enter .... it will boot the laptop with last setting
if this one not working then go for reinstall of xp ...for reinstall xp
- Start your computer from the Windows XP CD. To do this, insert the Windows
XP CD into your CD drive or DVD drive, and then restart your
Note To boot from your Windows XP CD, the BIOS settings
on your computer must be configured to do this.
- When you see the "Press any key to boot from CD" message, press any key to
start the computer from the Windows XP CD.
- At the Welcome to Setup screen, press ENTER to
start Windows XP Setup.
- Read the Microsoft Software License Terms, and then press F8.
- Follow the instructions on the screen to select and format a partition where
you want to install Windows XP.
- Follow the instructions on the screen to complete the Windows XP Setup.