Wrong place too ask ..but no one is ever in the assembler forum

[Sophtware]

Ok here is mah deal

I have pass32 assembler..and when i try to assemble a file
to an .exe i get a error that says this:

Pass: 1
Pass: 2
FATALOS Extender not found!


What the hell is a DOS extender? and where do or how do i fix this problem.

PLEASE HELP! Anything a comment, a website, a clue anything cause i havent the slightest idea!