Msg 15025, Level 16, State 2, Line 1

The server principal '[DOMAIN\Faizal]' already exists.

To resolve the Error

1. SELECT SUSER_SID('DOMAIN\Faizal')




0x010500000000000519000000D114792BZ53ZB44C8C29BC2Z1F509700




2.SELECT * FROM sys.server_principals 

WHERE sid =0x010500000000000519000000D114792BZ53ZB44C8C29BC2Z1F509700

3. Get the Login Name and Drop it as follows

DROP LOGIN [DOMAIN\Faizal]