I have a Dell Inspiron 5160 laptop running XP.  Yesterday I put it into sleep mode and when I came back to it later it had shut down.  I restarted it and it said something about shuting down because it got to hot.  When it started booting up it comes up with a message that says NTLDR is missing press crt+alt+del to restart.  I have tried to boot from the XP installation cd, but it never loads up.  How can I fix this problem?