I've been using Windows for about a decade now and I am planning to switch to another Operating System which is similar on how Windows Operates. I am currently using Windows for academic purposes such as writing document in MS Office Products, programming using Dev C++, Photoshop etc. These application are crucial since I am studying Computer Engineering and needed an OS that can handle IDE application and similar products like AutoCAD.

Can anyone suggest a different OS that maintains its user friendly interface and can provide similar function from Windows?

However, is it possible to install two OS in one PC?