when ever i play dos games they go a little off to the right side of the screen, why?
(this doesnt happen with doom)

Are you using DOSBox? I had the same trouble, fixed by setting the following in my dosbox.conf:

fullscreen=true
fulldouble=false
fullfixed=true
fullresolution=800x600

This means I have a fixed 800x600 display in the middle of my 1024x768 TFT screen, but you stop noticing very quickly, and it saves repositioning the display every time. (The first line also means DOSBox opens in fullscreen mode).