SharePoint Site Error: Service Unavailable HTTP Error 503. The service is unavailable

When opening My SharePoint site it giving me the error ‘Service Unavailable HTTP Error 503. The service is unavailable’ and I was not able to access either of them.

It was stopped at the IIS when i'm start manually i got the same error. I realized that I had just changed the password of my account. So here is share what I did to solve the problem.

1. Open up IIS Manager and click on 'Application Pools'.

2. Locate your App Pool account and right-click on it and select 'Advanced Settings'.

3. Under the Process model Group click on 'Identity' then Application Pool Identity Pop up is opened Click on 'Set' and re-enter My User Name, Password and Confirm Password then click on 'OK'.

Error is cleared...

Hope it will help you...