Many customers are very keen on security aspects. So to make sure that , sharepoint session cookies cleared off, when a user closes the window, and to make user login into sharepoint portal every time, we should do the following settings.
$sts = Get-SPSecurityTokenServiceConfig
$sts.UseSessionCookies = $true
$sts.Update().
At the command prompt, type iisreset /stop. IIS will attempt to stop all services and will return confirmation once all services have been stopped.
At the command prompt, type iisreset /start.
Happy SharePointing :-)