MSSQL Error 'The underlying provider failed on Open'

Question

I was using an .mdf for connecting to a database and entityClient. Now I want to change the connection string so that there will be no

Answer 1

I have solved this way.

Step 1: Open Internet Information Service Manager

Step 2: Click on Application Pools in left navigation tree.

Step 3: Select your version Pool. In my case, I am using ASP .Net v4.0. If you dont have this version, select DefaultAppPool.

Step 4: Right click on step 3, and select advanced settings.

Step 5: Select Identity in properties window and click the button to change the value.

Step 6: Select Local System in Built-in accounts combo box and click ok. That's it. Now run your application. Everything works well.

Codeproject Solution : the-underlying-provider-failed-on-open