I know you guys are trying to help , but I tried your suggestions and still no speed improvement.
I mean , in my solution I have 5 projects located each one in a folder in DesktopModules
Each projects consists only of VB and C# classes and user controls.
There is only Default.aspx file in the root of my DNN install folder.
Even if I uncheck in Build -> Configuration Manager the other 4 project that I am not currently working on , there is no speed improvement when I reload the page in my browser after some codebehing change in the project I am working at.
It's not Visual Studio that takes a long time to compile , actually it is pretty quick even when building the entire solution with all my 5 projects.
The problem is when i reload the page in my browser , because it takes about 40-50 seconds to render the page.
I've tried your first suggestion , not to rebuild the project after modifying the code behind file and only to re-open the page in my browser , but doing so , my code does not get updated. I still see the same result that I saw before modifying the code.
If you have any other ideas , I'm glad to hear them. Thanks for your answers !