Ok guys I see a lot of people in the comments talking about how anyone with basic computer skills would not fall for this, but I occasionally teach IT-related classes and let me tell you a few things:
1) A lot of people grow up not being taught shit about computers because they're raised with mobile devices and simultaneously told they already know everything about computers because they're part of a younger generation. That fucks up both a person's skills and their personal perception of said skills.
2) There's a lot of people who you'd expect to have computer skills but who don't. I once had to explain to an experienced web developer what browser bookmarks are. Stuff like that happens more often than you'd think. If you've somehow never needed to use a thing before, there's a good chance you won't know it exists.
3) Today's Windows and internet are not the Windows and internet we grew up with. Unfortunately the kids in your family are not learning HTML in order to build a custom Neopets storefront.
4) Not knowing these things does not mean you're stupid. Knowing these things does not make you immune to scams.
So let's take a look at the scam in the video:
The Windows key + R key is gonna open up your Run window, which looks like this:
This is not an online verification window: it's not a pop-up on a website.
This is a window on your computer itself. You can use this key combination regardless of whether you have internet.
You can use this window to open and run things on your computer. This can be both offline and online things.
The control key + V key pastes things. You normally use ctrl + C to copy something first, and then ctrl + V to paste it somewhere else. You can use this for example to copy text or a meme from a website into a new Tumblr post.
In this case, the scammer likely already has copied something for you that will automatically be pasted if you use ctrl + V.
So if you're now in the Run window and you use ctrl + V, something will be copied into that text bar in the Run window. This will be a bit of code that tells your computer to download a specific, malicious thing.
Once you press the enter key, you're telling your computer that you're confirming you want it to do what that bit of code says. It will now download and install that bit of malware on your computer.
If you don't have good protection against viruses and malware, the scammers can now fuck around with your computer and steal your sensitive info. This can result in things like your email suddenly sending out spam to everyone you know, your bank account emptying itself, or your computer becoming unusable.
TL;Dr: if something or someone online tells you to enter a specific combination of keys, don't do this unless you're a 100% sure what those commands do. If it does happen, do as the video says:
1) Disconnect your internet.
2) Run a scan for viruses and malware.
3) Change your passwords from a different device.
If you don't know how to do these things, ask someone to help you. Asking for help is never shameful. Someone helping you now is how you learn how to avoid future problems.
I'm on Linux these days so I'm not super up to date with current Windows antivirus stuff, but I'm sure there's other kind people on here who'll be able to tell you more about it.