I can not view viedoes. PC says to install flashplayer, flashplayer is already installed. Please hel

Please help me with Flashplayer.  I am no longer able to view videos such as Hilarious Videos.  Prompts me to install Flashplayer, when it is already installed.  I am very frustrated with Windows 8 and nobody I know likes it or is able to help me with it. I am about to return my new computer. Like I say I used to have it and this is a new computer.