Solution to dao350.dll Error

Dao350.dll is part of Microsoft Jet, a database/programming engine that is used by many popular Microsoft programs, such Microsoft Access. Programs that are created using Visual Basic also use this database/programming engine.

Error 1

You may receive the error message below when you install Visual Basic products:

“dao350.dll was unable to register itself in the system”

The error usually appears when “copying files” during the installation and system updating.

Why error occurs

The above error is reported because of corrupt or incorrect versions of the dao350.dll files.


To solve this issue, complete the instructions below:

  1. Click Start>All Programs>Accessories>Windows Explorer.
  2. Locate and double click C:\program files\common files\microsoft shared\DAO
  3. Locate Dao350.dll.
  4. Change the filename to Dao350.old.
  5. Insert your Visual Basic 6.0 disc in your drive.
  6. Locate and right click the Dao350.dll file on your Visual Basic 6.0 CD (the file is located in the \os\system folder), and click Copy.
  7. Right click C:\program files\common files\microsoft shared\DAO and click Paste.
  8. Click on Start, select Run.
  9. In the Open field, type the following phrase and then press Enter to register this DLL.

    regsvr32 “c:\program files\common files\microsoft shared\DAO\Dao350.dll”

  10. Install MDAC (Microsoft Data Access Components) 2.5 or above on your PC.

After you have successfully registered the Dao350.dll file and installed MDAC, proceed with the installation of Visual Studio 6.0.

In case you can’t install Visual Studio 6.0, get in touch with Microsoft Developer Support.

Error 2

You may encounter the following error when you launch the Report Wizard in Access 97:

“Error loading DLL”

Why the error occurs

Usually, the error occurs when the dao350.dll file is not registered.


To resolve the issue, you need to register the DLL using the regsvr32 command.

  1. Click Start, and then click Search.
  2. Click All files or folders.
  3. Type da350.dll in the box below all or part of the file name.
  4. Select Local Hard Drives in the drop-down menu.
  5. Click Search.
  6. The search result will appear in the right-pane of the search window. Note the path of the da350.dll file.
  7. Click Start, and then click Run.
  8. In the Open box, type the following command and then press Enter
    regsvr32 path\dao350.dll

Note: “Path” here is the path to dao350.dll. Typically, the path is C:\Program Files\Common Files\Microsoft Shared\DAO