This is the user agent for IE 11 on Windows 8.1 (Preview)
Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; Touch; rv:11.0) like Gecko
I am
I am finding the same problem with IE11 on IIS.
There was an official MS patch for IE10, but, they seem to have only fixed it for that explicit version, rather than for future (and, kind of expected) revisions of the browser.
Scott Hanselman provided a local project for IE10, and perhaps he will update it for IE11.
Here is a link to the patch for IE10 in .NET/IIS
The NuGet package for IE 10
Regarding the comment about not needing to use the .browsers file, I totally agree, however, this issue is (I believe) an issue with IIS/.NET 4
Cheers
Andy