Is there a native or custom MSBuild task available that returns the current OS version? Is there a binary that I could call via an Exec task? Or is there some other option?
Edit:
Peter Lang suggested the following link:
http://www.paraesthesia.com/archive/2009/07/06/getting-the-windows-os-version-in-msbuild.aspx
You can try with a registry key lookup as described in this post.