Mapped drive connection to network share may be lost

This article provides solutions to an issue where the mapped drive may be disconnected if you map a drive to a network share.

Original product version:   Windows 7 Service Pack 1, Windows Server 2012 R2
Original KB number:   297684

Symptoms

On a computer that runs Windows 7 Service Pack 1, 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.

Cause

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 quickly, if necessary.

Resolution

To resolve this behavior, change the default time-out period on the shared network computer. To do this, use one of the following methods.

Method 1: Using Registry Editor

Warning

If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

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

Note

You can't use this method to turn off the autodisconnect feature of the Server service. You can only use this method to change the default time-out period for the autodisconnect feature.

  1. Click Start, click Run, type regedit, 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 doesn't 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.

The 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:

  • Location: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\lanmanworkstation\parameters
  • Value: KeepConn
  • Data type: REG_DWORD
  • Range: 1 to 65535 (sec)
  • Default value: 600 sec = 10 mins

Method 2: Using Command line

Note

If you use this method, you may turn off the autotuning feature for the Server service.

To change the default time-out period for the autodisconnect feature of the Server service, open a command prompt, type the following line, and then press ENTER:

net config server /autodisconnect: number

where number is the number of minutes that you want the server to wait before it disconnects a mapped network drive. The maximum value for this command is 65,535.

Note

If you set the autodisconnect value to 0 (zero), the autodisconnect feature is not turned off, and the Server service disconnects mapped network drives after only a few seconds of idle time.

To turn off the autodisconnect feature, open a command prompt, type the following line, and then press ENTER:

net config server /autodisconnect:-1

Did this fix the problem

Check whether the problem is fixed. If the problem is fixed, you are finished with this section. If the problem is not fixed, you can contact support.

More information

Some earlier programs may not save files or access data when the drive is disconnected. However, these programs function normally before the drive is disconnected.

For more information about how to increase the default time-out period, Server service configuration and tuning