I was wondering if you can play this game in a window instead of full screen. I can't seem to figure out how to do it.

Any suggestions?

[edit]
Damn, forgot it requires 2.1 (which is free to get by the way), not 2000.

alt enter,

Go into the folder where Tyrian 2000 was installed and locate the file "dosboxT2K.conf".
Open with notepad. Change this line:

fullscreen=true

...to this:

fullscreen=false

Enjoy.

Flaser's suggestion here is the more complete one, opening the game in windowed mode every time, yet it's slightly more cumbersome.

An old game command to switch a game to windowed mode and back is the one SirCabbage mentioned: Alt+Enter