IE9 showing IE7 User Agent

I am testing applications from VS2010 with IE9, all was working ok then all of a sudden the IE9 browsers decides strangely that it wants to be IE7. When I query navigator.userAgent, it comes up with the IE7 user agent. What's up with that?!

Now the IE9 keeps thinking it IE7. I've never used IE7 before!?

How do I find my user agent in Internet Explorer?

To detect whether the current browser is Internet Explorer, you can make use of the navigator. userAgent property. The userAgent property returns the value of the user-agent header sent by the browser to the server. It contains information about the name, version, and platform of the browser.

How do I know my user agent?

That's where WhatIsMyBrowser.com steps in - we decode your user agent string to figure out everything it's saying. Check out our user agent analyser page, which gives you a neat breakdown of all the things we can tell you about your browser and computer based on your user agent.

Sometimes IE thinks a page will display better using an older Browser model or standard and will often switch to that. Press f12 and change the Browser mode and Document Mode back to IE9