My flash Player plugin Refuses to update.

I have avast antivirus and It shows me all the things that need to be updated such as google chrome, Flashplayer ActiveX (windows 8), Adobe Reader, and Flash player plug in.

Everything is updated, except for the Flash Player plugin, which whenever I try to update It says that its preparing for about 10 minutes then says that it failed.

Ive been looking around seeing what I should do, and what Im thinking is that I should download flash plugin from adobe again, but do I delete the old one?

My laptop has been acting wierd, I occasionally have to refresh to get the page to completely load, and video streaming is terrible.

On Youtube, it stops even though the gray buffer bar is far past the dot.

And on certain sites it says I need to install a codec to watch.

Im just really confused and lost.