If you encounter various errors when runing shared MS-DOS based database applications on your network, such as:
The file is in use
The file is already open
Unable to write to drive <X:>
The network drive <X:> is no longer available
these applications do not understand the Windows NT file locking mechanisms.
If you can't upgrade these applications, use regedt32 to navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
Edit or Add Value name, the following three (3) REG_DWORD values:
CachedOpenLimit - set the data value to 0 to prevent the caching of previously open files.
EnableOplocks - set the data value to 0 to turn off opportunistic file locking.
autodisconnect - set the data value to 0xFFFFFFFF to prevent the client workstation from being
disconnected due to a time out.
