Change SQL Instance name to default(local) instrance

I found some information, but, it didn't work.
Now, i open the enterprise manager, and My SQL Server name is
DENNIS\DENNISDB(windows NT), but i want to change this name to default
name(local), when i installed sql, i changed the instance name, i want
default name.
I used this method.
EXEC sp_dropserver 'DENNISDB'
go
EXEC sp_addserver 'DENNIS', 'local'
go
and i restart SQL Server Service and,
SELECT CONVERT(char(20), SERVERPROPERTY('servername'))
result : DENNIS\DENNIDB
select @.@.SERVERNAME
result : DENNIS
But, stil Instance name On My Enterprize Manager is DENNIS\DENNISDB, I want
"(local)" instance
Help me plase..Hi
As far as I know you cannot change/switch a default instance with a named
one. Re-install SQL Server only.
"DennisLee" <ddongdog@.haja.or.kr.korea> wrote in message
news:ONofqOsMGHA.2320@.TK2MSFTNGP11.phx.gbl...
>I found some information, but, it didn't work.
> Now, i open the enterprise manager, and My SQL Server name is
> DENNIS\DENNISDB(windows NT), but i want to change this name to default
> name(local), when i installed sql, i changed the instance name, i want
> default name.
> I used this method.
>
> EXEC sp_dropserver 'DENNISDB'
> go
> EXEC sp_addserver 'DENNIS', 'local'
> go
> and i restart SQL Server Service and,
> SELECT CONVERT(char(20), SERVERPROPERTY('servername'))
> result : DENNIS\DENNIDB
> select @.@.SERVERNAME
> result : DENNIS
> But, stil Instance name On My Enterprize Manager is DENNIS\DENNISDB, I
> want
> "(local)" instance
> Help me plase..
>
>