help...16 bit ms-dos subsystem

sumbody pleeze help me ... okae...whenever i try to run certain programs (including a dictionary, and ms-dos) i get a window titled

16 bit ms-dos subsystem

and says

C:\windows\system32\autoexec.nt. The system file is not suitable for running ms-dos and microsoft windows applications. Choose 'close' to terminate application.


When i run ms-dos i get the message:

ERROR: An extended memory manager is already installed.
XMS driver not installed.


I am pretty sure they are both related b/c when i run ms-dos i also get that '16 bit ms-dos subsystem' window.

I have Windows XP, have had my computer for along time, MS-Dos and my dictionary worked before. PLEEZE HELP ME!!..THANX

nevermind.....lol......fixed it

Damn - too slow.

BTW - It may help others if you post your fix back here.

TIA

well, turns out i was just missing the "autoexec.nt" file so i downloaded it and saved it back into my "system32" folder.... that was it! for sum reason it keeps deleting it every time i restart my comp tho...... thats still a mistery to me