Automatically disconnecting mapped network drive

If you map a drive to a network share, the mapped drive may be disconnected after a regular interval of inactivity, and Windows Explorer may display a red "X" on the icon of the mapped drive. However, if you try to access or browse the mapped drive, it reconnects quickly.  This behavior occurs because the systems can drop idle connections after a specified time-out period (by default, 15 minutes) to prevent wasting server resources on unused sessions. The connection can be re-established very quickly, if required. To resolve this behavior, change the default time-out period.

Use Registry Editor to increase the default time-out period. To do this, follow these steps, and then quit Registry Editor:

1. Click Start, click Run, type regedit (Windows 2000 or Windows Server 2003) or type regedt32 (Windows NT 4.0), and then click OK.
2. Locate and then click the following key in the registry:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\lanmanserver\parameters
3. In the right pane, click the autodisconnect value, and then on the Edit menu, click Modify. If the autodisconnect value does not exist, follow these steps:
   1. On the Edit menu, point to New, and then click REG_DWORD.
   2. Type autodisconnect, and then press ENTER.
4. On the Edit menu, click Modify.
5. Click Hexadecimal.
6. In the Value data box, type ffffffff, and then click OK. 

he client-side session is automatically disconnected when the idling time lasts more than the duration that is set in KeepConn. Therefore, the session is disconnected according to the shorter set duration value between AutoDisConnect and KeepConn. To change the time-out duration in the client-side during a UNC connection, specify the arbitrary time in KeepConn.
Locate and then click the following key in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Service\lanmanworkstation\parameters

Value: KeepConn
Data type : REG_DWORD
Range : 1 to 65535 (sec)
Default value: 600 sec = 10 mins