In a Command prompt when I type fasm.exe test.asm > test.txt
I get the output in test.txt.

But, when there is an error in the source code(test.asm)
the error message never makes it into test.txt?

anyone know why that is and how to get the full redirection?

The errors are usually directed to StdErr, not StdOut.

This is standard Windows and *nix thing. You have to redirect StdErr to that file. Use 2> test.txt to redirect StdErr (2), or 1> for StdOut (1).

To do both use 2>&1 test.txt.

yeah annoying syntax I agree

Why would you want to redirect error messages? Most people don't want their output mixed with that. Hence it goes to stderr (also so you can still see errors on the screen when redirecting output to text.) If you use FASMW (or FASMD, heh), it will jump to errors for you.

FASMW works great