Download Microsoft Jet Oledb 4.0 [repack] »
If your ASP.NET or Classic ASP website throws this error on Internet Information Services (IIS): Open the . Click on Application Pools in the left sidebar. Select the application pool running your website. Click Advanced Settings in the right actions pane. Set Enable 32-Bit Applications to True . Click OK and recycle the application pool. Connection String Examples
, like Notepad or Calculator. If you were using a 32-bit application and needed to connect to an Provider=Microsoft.Jet.OLEDB.4.0 was your go-to connection string. Microsoft Learn The 64-Bit Crisis
What (e.g., Windows 10, Windows 11) and system architecture (32-bit or 64-bit) are you using?
If your website or web service connects to an Access database via Jet and crashes on a 64-bit server, change your Application Pool settings. Open the . Click on Application Pools in the left connections pane. Select the Application Pool assigned to your website. Click Advanced Settings in the right actions pane. Set Enable 32-Bit Applications to True . Click OK and recycle the application pool. 3. For End-Users Running Third-Party Software
Choose the version (x86 or x64) that matches your application's architecture. Update your connection string in your code. download microsoft jet oledb 4.0
Security patches for vulnerabilities within WDAC and JET components are routinely deployed via Windows Update. Ensure your hosting servers and client machines are patched.
The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine.
Download and install the (choose the 64-bit version, AccessDatabaseEngine_X64.exe ).
Never download Jet DLL files or registry patches from unofficial websites. They frequently bundle malware or offer corrupted file versions that can destabilize your operating system. If your ASP
Sometimes. You can use a manifest file or application configuration to redirect the old ProgID to the new ACE provider. This is fragile. Better to recompile or change the connection string.
If you are maintaining an older operating system and the driver is corrupt or missing, it was historically distributed via or specific service packs. Because Microsoft has retired these standalone downloads from their main portals, you must obtain them through official OS updates via Windows Update.
To use ACE, you should download the (which provides the 12.0 provider) or its newer equivalents. This is the genuine Microsoft download that resolves the "provider not registered" error for legacy applications. This package, available in both 32-bit and 64-bit versions, finally provides the native 64-bit database engine that developers have been searching for.
However, these service packs are now considered legacy and are not applicable to modern, fully-patched versions of Windows 10 or Windows 11. The core Jet engine files on these modern OSes are already more up-to-date than the final service pack, and attempting to install an old SP8 package from the early 2000s can lead to system instability. Click Advanced Settings in the right actions pane
While Jet 4.0 is highly stable, it is an aging technology. Consider the following best practices for modern environments:
Right-click your project in the Solution Explorer and select . Navigate to the Build tab. Locate the Platform target dropdown. Change it from Any CPU or x64 to x86 . Save and recompile your application.
Run the downloaded .exe as Administrator.
