How do I add a login to the "sysadmin" server role?

I am having trouble with the following scenario:

Windows Server 2008 Enterprise Edition, SQL Server 2008 Enterprise Edition, and Team Foundation Server all running on one machine.

I am trying to create a maintenance plan to backup the TFS databases. In order to do that I have to be able to work in the SQL Management Studio with an account that is a member of the "sysadmin" server role.

The only member of the "sysadmin" server role is the "SA" account. The "SA" account password was left blank during install. When I try to add a new login (my domain admin account in this case) to the "sysadmin" server role I recieve the error message noted in "ERROR MESSAGE 1" below.

If I try to log into the SQL Management Studio with the SA account via the SQL Authentication mode I receive the error message noted in "ERROR MESSAGE 2" below.

My goal is to either:

(A) Add another login to the "sysadmin" role
or
(B) Login to the SQL Management Studio with the "SA" account

Please help! Thank you.

ERROR MESSAGE 1:
 
Add member failed for ServerRole 'sysadmin'. (Microsoft SqlServer.Smo).
|_  An Exception occurred while executing a Transact-SQL statement or batch.
    (Microsoft.SqlServer.ConnectionInfo)
    |_ User does not have permission to perform this action. (Microsoft SQL Server, Error: 15247)
 
ERROR MESSAGE 2:
 
Cannot connect to <INSTANCENAME>
|_ Login failed for user 'SA'. (Microsoft SQL Server, Error: 18456)

                                
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:

Select allOpen in new window

201405-VQP-001

Experts Exchange powers the
growth and success of technology
professionals worldwide.

Try it Free

30 day free trial. Cancel anytime.

Learn More about How It Works

Experts Exchange powers the growth and success
of technology professionals worldwide.

  • Solve

    Experts Exchange is the tech professional’s trusted, on-demand resource for solving difficult problems, making informed decisions, and delivering excellent solutions.

  • Learn

    With unparalleled access to technical experts, verified real-world solutions, and diverse educational content, Experts Exchange enables personalized development of technology skills.

  • Network

    Experts Exchange gives you the professional exposure and valued relationships key to building the career you want.

Join the Network Today

See Plans and Pricing