By default, Windows can handle a maximum of 5000 open TCP connections. If your loads are higher, you may experience problems such as failed requests for new connections and poor performance.

To improve Windows’ ability to handle the connections, change the registry as described below.

(Important: Changes to the registry can cause serious problems, including inability to reboot your machine. You may want to make a backup of the registry before continuing. For information on backing up the registry, visit support.microsoft.com and type "registry editor" into the "Search" box. Instructions for working with the registry editor vary depending on your Windows version.)

  1. From the Windows Start menu, type Run and press Enter.

  2. From the Run dialog, type regedit and click OK to start the registry editor.

  3. In the Registry Editor, open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

  4. For IPV4, open Tcpip, or for IPV6, open Tcpip6.

  5. Select the registry subkey Parameters, and check the right panel for the registry entries MaxUserPort and TcpTimedWaitDelay.

    If these entries do not exist, create them:

    a. Right-click on Parameters.
    b. From the shortcut menu, select New, and then select DWORD (32-bit) value. A new registry entry, New Value #1, is added to the right side of the Registry Editor.
    c. Change the name of the new entry to MaxUserPort.
    d. Repeat steps a through c, changing the name of the second new entry to TcpTimedWaitDelay.

  6. Change the value of the MaxUserPort and TcpTimedWaitDelay entries:

    a. Select the entry.
    b. Press Enter, or right-click on the entry and select Modify. This will open the Edit DWORD Value dialog.
    c. Change the Value setting for MaxUserPort to 65534, and the Value setting for TcpTimedWaitDelay to 30.