Webflashing - 2009-10-16

Hi people, I'm having some trouble to use Nini.
As I read in many sites, I "installed" Nini using the commandline "gacutil.exe /i C:\WINDOWS\system32\Nini.dll".

After the Success notification, I start Visual Studio 2005, start a new Visual Basic project, and when I type "Imports Nini.Config" here comes the error:

"The type or namespace Nini can not be found… bla bla bla"

What am I missing?

Thanks.