I'm not sure that Marcus understood the question correctly. Are you looking for a ways to run a .NET application without installation of .NET?
Basically, Marcus is right: this is not possible. I would add: it also makes no sense as all .NET Frameworks come free of charge for legal Windows users; and it's easy enough to deploy re-distributable .NET Framework with your application. Or demand it as a prerequisite — this is your choice. Only a most extreme looser won't get it. :-)
However, I come across two approaches to avoid installation of .NET. They come with other, more important features and — unfortunately — are based on proprietary commercial products. See:
http://www.remotesoft.com/linker/[
^] (looks more interesting),
http://spoon.net/Studio/Features[
^].
Disclaimer
This is not advertizement! Maybe I'm not supposed to mention any commercial products at CodeProject, but my goal was exclusively to provide comprehensive help to best of my own knowledge. I do not have any affiliation with the teams marketing and selling the referenced projects, nor I have any interest in promoting them.
—SA