PRB: Visual Studio 6.0 - Error Message: Dao350.dll Was Unable to Register Itself in the System

When you try to install a Visual Studio product, you may receive the following error message: The problem occurs when the installation process completes the "copying files" part and begins the "updating the system" part.

This problem is caused by corrupted or incorrect versions of the dependency files of the Dao350.dll file.

To try to work around this behavior, do the following steps:

1. In the directory c:\program files\common files\microsoft shared\DAO, rename the Dao350.dll file as Dao350.old.
2. On the Visual Basic 6.0 CD, locate the Dao350.dll file, and then copy it to the directory c:\program files\common files\microsoft shared\DAO. (The Dao350.dll file is located in the \os\system folder on the Visual Basic 6.0 CD.)
3. To register this file, click Start, click Run, and then type or paste the following line:

   Regsvr32 "c:\program files\common files\microsoft shared\DAO\Dao350.dll"

4. Install Microsoft Data Access Components (MDAC) 2.5 or later.

If the Dao350.dll file is registered successfully in step 3, and if MDAC is installed successfully in step 4, try to install the Visual Studio 6.0 product.

If you cannot install the product successfully, contact Microsoft Developer Support. To do so, visit the following Microsoft Web site:

For additional information about installation issues for Visual Studio 6.0, click the article numbers below to view the articles in the Microsoft Knowledge Base: