If you in hurry have chosen wrong authentication for your web application and want to change

. In Central administration, there is no any option to change the authentication provider
. We must use PowerShell command to change these settings
. Thanks god for PowerShell
.

From Classic to claims:

$webApp = Get-SPWebApplication “http://webapplication”
$webApp.UseClaimsAuthentication = $True;
$webApp.Update()

From Claims to Classic:

$webApp = Get-SPWebApplication “http://webapplication”
$webApp.UseClaimsAuthentication = $False;
$webApp.Update()

We also can use 1 or 0 instead of $True and $False.