Frequently Asked Questions

error message "Class not registered" and "Cannot start Jet Engine"

Manual Installation for DAO350.dll file in 64-bit environment

In some cases of 64-bit Windows 7, 8, and 10 operating systems, the installation and registration of dao350.dll is blocked, either by anti-virus software or by Windows itself. BSI applications like Simian and WaveCart require the 3.5 version specifically for building an audio database as newer versions (3.60 / dao360.dll) are not backwards compatible. If you are receiving errors “class not registered” or “cannot start Jet Engine”, then you will need to manually register the DAO350.dll file.

Figure 1 - Common error messages due to missing or unregistered DAO350.dll

To manually install this component perform the following steps:

(If the file is not present on your system, a copy can be downloaded from and then moved to that folder).

Figure 2 - Folder location of DAO350.DLL

CMD searches in Windows 10, 8, 7
Figure 3 - Windows 10, 8 & 7 searches for Command Prompt "cmd" with right click menu option Run as administrator being selected

cd \windows\syswow64

regsvr32 "C:\Program Files (x86)\Common Files\Microsoft Shared\DAO\DAO350.DLL"

Figure 4 - Getting the correct syntax in the regsvr32 command is important. The word wrap is OK.

Figure 5 - Success!

 Last updated Thu, Jul 10 2014 1:26pm

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