It is possible to use the compile command (cl and link) in Command Prompt if I only installed the VS Shell (isolated) which is part of the Atmel Studio?
Neither Command Prompt nor Power Shell know the cl command!
Edit :I searched for cl.exe and the developer promt but didn't found it.
Edit : downloaded visual studio tools but still can not find the developer promt :(
Unfortunately I can't install the full visual studio version.
If you have the Developer Command Prompt for VS 2015 installed, you can.
Essentially, it's an application that opens a command prompt inside the directory C:\Program Files (x86)\Microsoft Visual Studio\2015\VERSION, where VERSION will depend on which edition of Visual Studio you have installed (Community, Professional, or Enterprise).
Otherwise you could cd into the folder where the compiler executable is and run it by typing its name, passing it parameters and pressing Enter, or you could add the path to it to your PATH environment variable (although I haven't tried this personally and can't vouch on how well this will work).