Compile to two .NET Frameworks at once

I have a program in C#, and I want to make it compile to two different .NET Framework versions.

So when I press the Compile button, it makes, for example, "ComputerInfo3.exe" and "ComputerInfo4.exe".

I want to use version 3.5 and 4 of the .NET Framework. I use Visual Studio and C#. Is this possible?