Smallvoid.com

When mapping a network share as a network drive, then Windows Explorer tells the remote server, that it should be notified by any changes made on the network share. If a file changes on the network share, then each Workstation registered as having that shared mapped as a network drive will get a SMB notification about the change. If many users are updating files on the network share, then it will cause a lot of traffic (bad for slow connections like VPN or dialup) and can make the tree-view in the File Explorer flicker.

To configure whether Windows Explorer should register for events happening on the mapped network share:

[HKEY_CURRENT_USER \SOFTWARE \Microsoft \Windows \CurrentVersion \Policies \Explorer]
NoRemoteChangeNotify = 1

More Info MS KB Q812669

Windows XP and Windows 2003 extends the event registering from just being the root-folder, to actually be all underlying sub-folders and their files (Even more traffic). To change this back to only register for events happening in the root of the mapped network share:

[HKEY_CURRENT_USER \SOFTWARE \Microsoft \Windows \CurrentVersion \Policies \Explorer]
NoRemoteRecursiveEvents = 1

More Info MS KB Q330929
More Info MS KB Q816375
More Info MS KB Q885189

Note if using software which relies on being notified of file changes and its files are placed on a mapped network share, then this change in policy might give unpredictable results.

Note only WinXP SP2+ reacts to the registry entries above, or if having applied the Critical Update Q810565.

More Info MS KB Q831129