DOS : Increase Dosbox screen size in Windows

Step 1. Find dosbox-0.74.conf

Step 2. Modify the SDL part in the dosbox-0.74.conf

[SDL]
fullscreen=false 
fulldouble=false 
fullresolution=original 
windowresolution=1024x768 
output=ddraw 
autolock=true 
sensitivity=100 
waitonerror=true 
priority=higher,normal 
mapperfile=mapper.txt 
usescancodes=true 

ps. Some Dos application may consume lot of CPU usage. Fix it by Setting a fixed CPU cycles, for example, 16000.
[CPU]
cycles=auto 
cycles=16000