Most useful d2loader parameters

-mpq load cdkey mpq
-w -window switch window mode
-lq -lowquality decreases the quality of graphical aspects
-ns -nosound disable all sound
-skiptobnet -skiptobnet go battle.net directly
-title -title set window title to
-noplugin -noplugin do not load plugins
-res800 -res800 start window in 800x600 (for d2)
-res640 -res640 start window in 640x480 (for d2)

For example:
C:\Diablo2\D2Loader.exe -w -mpq pub1.mpq -title "pub1" -skiptobnet -noplugin -res800 -lq -ns

d2loader download:
http://www.itempub.com/LinkFile/download/D2Loader.exe