Identifying SQL Server/Agent start up account using T-SQL

--SQL Serer
DECLARE @test varchar(20)

EXEC master..xp_regread
@rootkey='HKEY_LOCAL_MACHINE',@key='SYSTEM\CurrentControlSet\Services\MSSQLSERVER',
@value_name='ObjectName',
@value=@test OUTPUT

SELECT @test

--Agent

DECLARE @test varchar(20)
EXEC master..xp_regread
@rootkey='HKEY_LOCAL_MACHINE',
@key='SYSTEM\CurrentControlSet\Services\SQLSERVERAGENT',@value_name='ObjectName',
@value=@test OUTPUT

SELECT @test