Procedure for Disabling OPLOCKS on Startup

When Windows 2000 Server, Windows NT, or plain old Windows 2000 is running on your server, the “Oplocks” feature should be disabled as it may hold ‘open’ transactions that should be processed immediately.  Errors referencing “Jet Database error” and “Unrecognized Database” could otherwise result.

1. On the file server machine where the database resides: Click on ‘Start’ and then ‘Run’.  In the “Run window” that appears, key-in the word Regedit then click the “OK” button.

Now select the following key using the “+” sign to the left of each level in turn to open the selections below that level, one level at a time:

      +HKEY_LOCAL_MACHINE

+SYSTEM

+CurrentControlSet

+Services

+LanmanServer

Parameters

2. Once reaching the Parameters level and you have ‘opened’ that folder: right mouse click, then left mouse click on “New”, then select DWORD.  It will be ready for you to name this DWORD.  Key-in the single word: EnableOplocks.  The default value will already be zero.  Leave the default value at zero and then close regedit.

3. Re-boot the file server machine.  At this point OpLocks will be disabled from the start, and this should avoid the Jet corruption problem or unrecognized database errors.

4. In a small number of cases these same errors may also be caused by power surges, brown-outs, workstations abruptly powering down with AA running, bad network cables, network cards, or almost anything else on the network.  Sometimes playing musical chairs can isolate the offending workstation, or network device.  In most cases disabling OPLOCKS should reduce the frequency of these errors however.