Re: .net framework questions.....
The .NET framework is what developers use to create Windows applications, but it's also what end users need to have installed for these applications to run. It's becoming more tightly integrated into Windows and more and more Windows software is using it so yes - you should keep it installed, whether you intend to program or not.
As celegorm said, you should keep it updated as well because of a security standpoint if nothing else.
Save the whales, feed the hungry, free the mallocs.