Flash Player for IE is integrated into the browser by Microsoft. It cannot be updated or installed from here, because a specific Windows update prevents it. For IE, you can only update Flash Player via Windows Update.
However, IE11 (installs with Windows 8.1) has been a "rolling train wreck", which Microsoft has been aware of since October 18 when they released it. The pages can't recognize the browser, so they don't recognize any of the plugins, like Flash Player. So far, Microsoft has made NO indication that they have any plan to fix it soon.
Microsoft's recommendation is to use Compatibility View for affected pages, and "pretend" you're using an different browser. Trouble with that is it has seen limited success at best, and you have to individually enable it for EVERY page that has problems.
I'm not big on "pretending" so I recommend actually using another browser.
ANY of those will work where IE11 won't, with the Flash Player Plug-in (For all other browsers), and Chrome doesn't even need that because it has its own Flash Player plugin built in.