If you’re developing multiuser Jet-based applications, you probably know about Microsoft’s msldbusr.dll. It allows you to read the Jet lock files and get the correct number of connected users and computers they connect from. However, if you use this unsupported DLL, keep this gotcha in mind: If you include the DLL in a VB application installation and the user is running an early Windows 95 version, the DLL disappears when the user shuts down his or her machine.
To solve this problem, include an uncompressed copy of the DLL with your setup. If, after a reboot, the user manually copies the file back to the Windows system folder, it will stay there forever and give you back your functionality. This oddness does not occur when installing to Windows 98 or NT.