Waiting . . .
Success for setting a pixel in a DOS window!
I attached to this message 'setpixel.c'
In a DOS window in mode 13h it draws a little smiley face out of a few set pixels compiles in Turbo C.
Thanks for all your suggestions everyone! (But, in the end, it was a friend who wrote the function to set pixel)
I'll try swoopy's code later, my includes messed up.