I think its a software issue. All of the Youtube videos I try to play stutter visually while the audio plays fine. Most of the time, whether it be from skipping through the video more than twice or just randomly, the video will freeze and start buffering, even though the video is fully loaded. This doesn't happen with other programs running Youtube videos (such as Discord). With my hardware, I don't think this should be happening (i5 7300hq, 8gb ddr4 2400mhz ram). This has been happening for a few days now.

@sgunhouse As stated in the last part of my question, this is a new computer with no antivirus installed. Windows Defender is disabled.

Every time I try to download some zip files, every other zip file shows up with a virus detected warning.

I've tried downloading a Minecraft texture pack, but every (and I mean every) download I've found supposedly has a virus in it, and Opera won't let me download it. How can I bypass this built in Antivirus?

For the record, I have zero antivirus installed, and this is a brand new computer I got earlier today.
https://minecraft.curseforge.com/projects/realistico