I know that I can use Arrow Keys to collapse items of solution explorer one by one, but I would like to know if there is a way to collapse all items with only one operation. I w
Use the Visual Studio extension that fits your version of Visual Studio.
In my case (I use Visual Studio 2012) I use the extension Productivity Power Tools, but, unfortunately this exist only for VS 2010 and latter... For VS 2008 there is a similar extension: Power Commands.