A Github (Bitbucket, Gitlab, Gitbucket, Gitorious) alternative that you can self host on your Windows server.
Checkout out the Getting Started guide to install and use WebNetGit.
View the License.txt file for more details.
mattias197711/WebGitNet
WebGit .NET is an ASP.NET MVC app that provides access to your git repositories over HTTP. It supports browsing in a web browser AND push / pull over Git's "Smart HTTP protocol".
C#Zlib