cannot set security to SQL server and windows

[thefrstgatsby]

I have set up sql server personal edition on my machine. When I go into the SQL server properties, then to the security tab, I cannot change the authentication setting to SQL server and windows, it keeps defaulting back to just windows.

I have tried doing it with the service stopped and to no avail.

I need this because whenever I try to connect to the database, it keeps saying: Login failed for user 'sa'. Reason: not associated with a trusted SQL server connection.

I researched that error and most posts recommend that I set authentication to SQL server and windows.

Any help is appreciated

 

[JayKusch]

Are you logged into that machine w/ an Admin account?

Thanks

J. Kusch

 

[JBaileys]

When SQL Server was installed, you have an option of windows authentication or mixed (windows and sql).
Which option was selected?