Well, you can use their OS, which has for years tried to undermine the free and open source communities, but you have to pay for it. And you have to agree for them to spy on you. And you're poor?? That is okay, just give up more of your privacy rights and we already sold all your data, so you will be a good consumer now.
You run Windows. Your mind belongs to us. Your ability to think beyond .NET and C# will soon diminish, and we will give you some mediocre job now based on your mediocre proprietary skills, and your role as a tech worker now be to spread your love for MS to everyone, because if you don't we will stop paying you, and you will have no food and no home. And you will not know how to use anything but Windows.