install integration service on existing instance

I need to install Integration Service on an existing SQL 2005 instance. Is
it possible add components to an existing instance or do I need to create a
new instance of SQL server?
When you install SSIS on a Server, the service is "stand alone", not bound to
a specific instance. You can install SSIS alone, running the setup and asking
for the installation of the Integration services without install the other
components
Gilberto Zampatti
"Mike" wrote:

> I need to install Integration Service on an existing SQL 2005 instance. Is
> it possible add components to an existing instance or do I need to create a
> new instance of SQL server?
>
>