Stop a network drive from automatically mapping
From How to connect and disconnect a network drive in Windows XP:
Disconnect from a mapped network drive
- Double-click
My Computer. - Right-click the icon for the mapped drive.
- Click Disconnect.
If it still returns, do :
net use /persistent:no
and then reboot. When you now log in, all of your mapped drives should be gone and you can remap the ones you need.