I am running Windows 8.1 on my laptop and have current versions of Firefox, Chrome and Internet Explorer on this machine. Most of the time, everything works okay but from time to time - and seemingly more often as time progresses - I have trouble playing the video portion of videos. It doesn't seem to matter which browser I use, although I mostly use Firefox: the audio plays fine but the video portion is either solid black or solid green - usually green. It also doesn't matter where the video is - on YouTube or embedded in a news website - I get the same nonsense. It will be like this for a few days then suddenly everything is fine again even though I did nothing but curse in most cases. I've always assumed that the next Firefox update fixed the problem and then the one after that re-introduced it or that Windows Updates were causing the problem and then fixing it.

Can anyone tell me for certain what causes this problem and what the solution is? I am REALLY tired of this horseshit!