NTLDR Error on Inspiron 9400

Hi People,

I'm new to all this so please forgive any errors in my request. I'm running windows XP professional.

I left my laptop on last night and when I went to it this morning I found a black screen with the error message NTLDR  is missing on it. It said to press control+alt+delete to restart, I did this but it keeps taking me back to the same NTLDR is missing screen.  Now, this is what I have tried so far;

Re-boot from install disk - won't do it, just keeps taking me back to NTLDR screen, have tried everything I know.

Re-started pressing F12 a went through that scenario

Re-started pressing F2 same thing.

Turned off laptop and re-started with F8 and Media Direct button, no good.

Started it just with Media Direct button, no good.

Called Dell Tech Support.........only work Mon-Fri..........must be recession

I wend through F12 agan and done a FULL Diagnostic and this error came up, any one know what it is and what to do now?

PMOVI Test;

Error Code 0123

Msg: Error Code 2000:0123

Msg: Memory Integrity test Faled

Address= 0_5DDDFEFCH, Actual = AAAAAA2Ah, Expected = AAAAAAAAh

Location = DIMM_B

Any help would be greatful