Joining a Vista Machine to a Windows Domain

With Windows XP a VPN tunnel has to be created first for everyone, then join  the domain. After reboot, use the logon using dial-up networking feature to create a cached profile on the local machine. Make sure to add the domain user to the local administrator group, to allow configuration changes for the new profile.

In Vista there is no logon using dial-up networking option. Create a VPN tunnel to the Microsoft network, join the domain, then reboot. Logon as the local administrator, reestablish the VPN tunnel, then switch users via CTRL-ALT-DEL and logon as the domain user. Make sure you use DOMAIN\USER as the account.