Sooner or later the Microsoft MSTSC.exe command is going to be your best friend. With that in mind:
- Usage for XP:
MSTSC [<connection file>] [/v:<server[:port]>] [/console] [/f[ullscreen]] [/w:<width>]/h:<height>] [/public] [/span] [/edit "connection file"] [/migrate]
- Usage for Vista SP1:
MSTSC [<connection file>] [/v:<server[:port]>] [/admin] [/f[ullscreen]] [/w:<width>]/h:<height>] [/public] [/span] [/edit "connection file"] [/migrate]
Note that Microsoft has seen fit to rename the /console command /admin in Vista SP1 which installs version 6.0.6001.18000 of MSTSC.