In a previous tip, “Change disconnect timeout for network shares,”
we explained how to use the /AUTODISCONNECT switch with the NET CONFIG
SERVER command to change the timeout value. The timeout value determines
how quickly Windows 2000 disconnects network connections. Although it generally
isn’t an issue on Windows 2000 Professional computers, there’s one side effect
to using the /AUTODISCONNECT switch: It disables autotuning
in Windows 2000.

When
Windows 2000 boots, it automatically sets the parameters for the Server
service, configuring the service according to various factors, including the
amount of RAM in the system. However, when you use the /AUTODISCONNECT,
/SERVCOMMENT, or /HIDDEN switches with NET CONFIG SERVER, Windows 2000
writes the configuration values to the registry. When the system boots, it no
longer autoconfigures the service because the values
already exist in the registry. So, for example, if you add memory to the
system, the Server service won’t reflect the change.

You
can restore Windows 2000’s ability to autotune the
Server service by removing some of the values from the registry. To do so, open
the Registry Editor and open and select the key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\
LanmanServer\Parameters. Now choose Registry | Export
Registry File and make a backup copy of the key. Then, delete all of the values
in the key except:

  • EnableSharedNetDrives
  • Lmannounce
  • NullSessionPipes
  • NullSessionShares
  • Size

(Once
again, do not delete these values.)

Exit
the Registry Editor, reboot the computer, and Windows 2000 will be able to autotune the service again.

Note:
As always, we’ll remind you that editing the registry can be risky, so be sure
you have a verified backup before making any changes.

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