No, no... goos suggestion but wrong way to look it at....

Image running just DOS, ok? (Leave windows behind/out of this)....
Then image running Doom on your computer....
Then picture having Doom running in a "window", centered on your screen with a 2" border around it.......

______________
| ___________ |<---whole screen
| | | |
| | DOOM |<------Doom
| | | |
| |__________| |
|_____________<---Black