How do I set different default printers for my laptop, depending on whether or not it is docked?
The default printer in Windows XP is a per-user setting, and, to my knowledge, can’t be changed for the same user in different circumstances (ie docked/undocked). But different users can have different default printers. So set up two users, one for when you’re docked, and one when undocked. If you need to work on the same material from two different logins, you can place it in the Shared Documents folder so that both logins can access them.
