Setup a batch script in the users Startup folder and map the drive in the batch script using the NET command.
For example:
net use x: /delete
net use x: \\server\share1 mypassword /user:mike
This removes any original mapping for drive x: and then maps drive x: to \\server\share1 using the username mike and password mypassword
If you don't want the lines visible when the batch script runs, put @echo off on the first line like this:
@echo off
net use x: /delete
net use x: \\server\share1 mypassword /user:mike
This will run each time the machine powers up or logs in (depending on configuration)
