Answer 1

To enable the sa account, see http://msdn.microsoft.com/en-us/library/ms188670.aspx

Answer 2

Answer 3

Answer 4

Are you an administrator of the SQL Server? Or maybe I should ask that as, "Do you think you are an administrator of the SQL Server?" Execute SELECTIS_SRVROLEMEMBER('sysadmin') It will return 1 if you are an administrator and 0 if you are not.

What error are you receiving?

Answer 5

You should be memeber of the server roles either "SYSADMIN" or "SECURITYADMIN" to unlock  the 'sa' login.

IS_SRVROLEMEMBER('sysadmin')= 1

print'Current user''s login is a member of the sysadmin role'

IFIS_SRVROLEMEMBER('sysadmin')= 0

print'Current user''s login is NOT a member of the sysadmin role'

IFIS_SRVROLEMEMBER('sysadmin')ISNULL

print'ERROR: The server role specified is not valid.'

IS_SRVROLEMEMBER('securityadmin')= 1

print'Current user''s login is a member of the securityadmin role'

IFIS_SRVROLEMEMBER('securityadmin')= 0

print'Current user''s login is NOT a member of the securityadmin role'

IFIS_SRVROLEMEMBER('securityadmin')ISNULL

print'ERROR: The server role specified is not valid.'