Sharepoint 2010 Convert classic to claim based authentication

You already have a Web application created using Classic Mode Authentication and you want to convert Web application from Classic Mode authentication to Claims based Authentication.

You don’t have to delete that web application. You can convert that web application from classic mode authentication to claims based authentication. However this can only be done using PowerShell and it’s an irreversible process. Follow PowerShell commands to convert the web application from Classic Mode Authentication to Claims based Authentication:

$App = get-spwebapplication “URL”

$app.useclaimsauthentication = “True”

$app.Update()

Example:-

$App = get-spwebapplication “http://webapp:1907”

$app.useclaimsauthentication = “True”

$app.Update()

Warning!: This is an irreversable process.