My advice... don't use dos box for Mechwarrior 2. The game will usually launch on its own if its gonna launch at all.
lordlupin, Mechwarrior 2 (all of them) is very picky. The games were designed in an era where having two CD drives on the same computer was almost unheard of. So if you've got multiple CD drives, the fact that your main CD drive is F probably is part of your problem. So like dosfreak suggested, change the letter of one of your CD drives to D: and see if that helps
qbodsyt, as was pointed out, your batch file was totally messed up. But if fixing it up didn't help, do the following:
-Go into your mech2 directory
-Right click on the exe file, and hit properties
-Go into the program tab, and uncheck the box "close on exit"
Now you'll see a PIF dos shortcut file appear. Use that to run the game. Attempt to do as you did before, and get it to crash. Then you'll be able to see the error message, if any.