Office XP Word opens very slowly..

I doubt that it is related to AD. It is probably to do with file location under the options in word pointing to a location that ether does not exist in your new environment and you are waiting for the timeout, or the location is a networked location and you are waiting for authentication to reconnect to that location. If it is slow every time, then I would guess the first problem.

Try deleting/renaming Normal.dot

This happens when u have network mapped drives.