You can't get a free visual studio but you can download the .NET framework SDK for free. If you are a student you can get the Visual Studio for about $100.00. However you don't need it to run .NET programs.
To get started without a development studio. Go to the http://www.asp.net site and click the download link to get the .NET Framework Redist. Next, go to the same site and download the .NET Framework SDK link. You can now write all your code in a text editor and run it through your browser on the IIS.
I think that was your question.