1. Once logged into your server, open IIS Manager. You can do this by clicking your Windows Start button and entering "inetmgr" into the search box. Then press enter.
2. On the Connections pane, expand the server node and click "Application Pools."
3. Right click on your application pool and select "Advanced Settings..."
4. Change "Enable 32-bit Application to True."
- Select the app pool for your web app.
- Click Advanced Settings… under Edit Application Pool on the right.
- Change the value of Enable 32-Bit Applications under (General) to True.
IIS Advanced Settings Enable 32-Bit Applications
Note that the word “Enable” in the setting doesn’t mean “allow” as in “allow either 32- or 64-bit applications.” It actually means “force” as in “force the worker process to run in 32-bit mode so that 32-bit applications are supported.” This means that the app pool worker process will always be launched as a 32-bit process when this setting has a value of True. Setting it to False will launch a 64-bit app pool worker process.
Note that when an app pool worker process is started, it shows up in the Image Name column on the Processes tab in Task Manager as w3wp.exe. When the Enable 32-Bit Applications setting has a value of True, it will be listed as w3wp.exe *32.
5. Click "OK" to finish.