Stuttering Video

Hello all:
I've discovered a strange phenomenon with my my video music files on my C drive. IT seems that random video files have exhibited some strange behavior. I have a ton of videos I've saved from various sites that are now stuttering when I play them. It doesn't seem to have any rhyme or reason to it. After hitting "play", the first stutter appears about 20 seconds in, then repeats every 20 seconds or so thereafter. Obviously this ruins the listening/video experience. Re-downloading the video doesn't always solve the problem, and sometimes I can't even re-download to solve the issue. This happens regardless of what type of video file I use, or from which site I download it from. I should mention that I'm using KeepTube to download these videos.

Anyone else having this issue and know of a solution?

If you have only Hard Disk Drives, I recommend trying a defragmentation of each of them. Clean up your computer, check for viruses with an ainti-virus program (Anti-Malware, Virus, Spyware Protection | Microsoft Security Essentials, you might also try Malwarebytes : Malwarebytes Anti-Malware PRO removes malware including viruses, spyware, worms and trojans, plus it protects your computer)...

In a command prompt (type cmd into the windows search bar, RIGHT-click and click "run as administrator", and enter any password prompt it gives you), type SFC /Scannow

make sure you have restarted your computer at least once in the past few days

go into comtrol panel>uninstall a program (sub-link under programs), and uninstall every program you do not really use or need.

Use this great tutorial brought to you by our fearless leader Brinks: Optimize Windows 7
You do not need to go out and buy anything, so if there is an option you cannot do or do not want to do, skip it and go to the next. Trust me, this tutorial is a great way to speed up your computer. If you still have trouble, let us know.

ps. some of the things mentioned in the tutorial are for extremely advanced users, so if you do not know how to do something, do not worry, just skip it