Flash Player for IE on Windows 8 & 8.1 is mebedded by Microsoft.
It can ONLY be updated via Windows Update.
IE11 is another can of worms.
Microsoft intentionally screwed up the "user-Agent Strings", which websites use to identify the browser and provide the proper content for it. Since the pages can't recognize the browser, 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.