TF255507: The security identifier (SID) for the following SQL Server login conflicts with a specified domain or workgroup ...

TF255507: The security identifier (SID) for the following SQL Server login conflicts with a specified domain or workgroup account: {0}. The domain or workgroup account is: {1}.  The server selected to host the databases for Team Foundation Server is: {2}. 
You can resolve this issue by renaming the conflicting login. To do so, open a command prompt on the computer that is running SQL Server and execute the following command:
sqlcmd -E -S "{2}" -Q "ALTER LOGIN [{0}] WITH NAME = [{1}]"
For more information, see the following page on the Microsoft Web site: http://go.microsoft.com/fwlink/?LinkId=183408