I don't know how to disable the notification and I may have looked for this back in the Windows XP days and never found a solution. However I have an easy work around if your user name and passwords are the same on your server as the workstation.
Make short cuts to the mapped drives on your desktop, you can move them to your a place of your liking later. Open a command prompt and type:
net use * /d <enter>
net use /p:no <enter>
The code will remove your mapped drives and stop the machine from re-mapping them every time you log on. When you click on your shortcuts you will re-map the drive(s). Note: This will only work if the server is up and running, if the server is off or the server has not fully booted it will not work.