http://www.truecrypt.org/
TrueCrypt.exe /q /v d:\tools\TrueCrypt\090427.pdk /lz
TrueCrypt.exe /q /dz
Mount the volume d:\myvolume as the first free drive letter, using the
password prompt (the main
program window will not be displayed):
truecrypt /q /v d:\myvolume
Dismount a volume mounted as the drive letter X (the main program
window will not be displayed):
truecrypt /q /dx
Mount a volume called
myvolume.tc using the password MyPassword, as
the drive letter X.
TrueCrypt will open an explorer window and beep, mounting will be
automatic:
truecrypt /v
myvolume.tc /lx /a /p MyPassword /e /b