Hello.
NTLDR means that part of (or all) the OS is missing. Reintall the OS using the hidden hard drive partition or media.
Do you have a XP CD? If so, press F12 during startup and choose to boot from the DVD\CD ROM.
Laptop didn't come with media? Try to press F10 or F12 while booting to see if there is a recovery partition on the hard drive.
To test the hard drive, try pressing CTRL+ALT+SHIFT+D immediately after power-on.
If you want to test all components press F12 during boot up and choose to use the Dell Diagnostics.
I hope that helps!