Problem

The SQL Server service won't start.  When trying to start it manually, it says there is a logon failure.

 

Cause

Apart from the password of the account running that service being wrong, this can also be caused by a change affecting account trust, such as joining/leaving a domain.

 

Solution

  1. Open the Services snap-in (services.msc)
  2. Right-click the SQL Server service for the desired MSSQL instance, and click Properties
  3. Open the Log On tab
  4. Do one of the following and click OK:
    - If the account being used is "NT Service\MSSQLSERVER", blank out both the Password and Confirm password fields, and click OK
    - Provide the credentials of another account with local administrator permissions, and click OK
  5. Start the desired SQL Server service