Blocky/Pixelated Video Playback Help

[MejraThea]

Sometime last week my computer started having choppy video, when I played it from a file on my computer/external hard drive. Today, a few hours ago, I started getting what my friend supplied as being "Blocky/pixelated" playback. I have taken screenshots. One / Two

So far I know it happens on YouTube, on Tumblr. It happens on files I play on my computer itself. It does not happen on Netflix, though.

It does it on any type of video, even if that video is just one unmoving picture. It doesn't not affect the audio.

Can anyone help me to fix this?

My information is: Windows 7, Gateway ZX6900, Intel Core i5 CPU 650 @ 3.20 GHz, RAM 4.0 GB (3.80 usable), 64 bit.

 

[Mussels]

if you rewind the video, does the second playback work?

I had this for a while and updating my video card drivers resolved it.

 

[MejraThea]

If I recall correctly, rewinding or changing spots in the video didn't change anything. I will try updating my video card drivers though, thank you.

Edit: That seems to have done the trick! Sorry to make a thread for an issue that was so easily fixed. However, I really appreciated the timely and extremely helpful answer, Mussels. I'll be sure to remember your forum for future use, or to contribute my own answers.