I have Windows 8.1 Internet Explorer 9. It says I have Flash 16.0.0 preinstalled but it is not in the list of installed programs in control panel.
I keep trying to install it but I get that same message. I'm trying to use jigsawpuzzles.com but need the Flash.
Flash Player is a built-in component of Internet Explorer. There's no separate program or download.
IE11 introduced a number of changes in how it identifies itself to remote websites, and this in turn may cause some sites to not detect Flash Player even if it *is* present. You can verify that Flash is working correctly by looking at a simplistic Flash site like http://www.homestarrunner.com/. If it's working, Flash is definitely there and enabled.
The easiest workaround for affected sites is to just use a different browser, like google chrome - http://www.google.com/chrome/