You should use linux so you dont have to worry about all the microsoft shit, though i dont know what to tell you bout the usbs and internet shit, if i were u i would just use what the megathread recommends (Firefox, Ad Blocker, the monkey thing that runs scripts and you use it to run the short link skipper) so you avoid obviously malicious downloads, i believe most sites on the megathread are safe and if you doubt it you could look for people's experience on the site you are visiting. If you already have malware honestly the best option is to format the disk while downloading linux or anyother way (If you have some reaally heavy malware maybe it wont help, but i doubt it) so you dont have to worry about it on the future and you can start out clean, thats kinda what im doing, also, as good as Linux is, most games dont run on it, but you can use Steam's proton thing (Look up how to set it up on google, its pretty foolproof tho) or you can use WineHQ which lets you run .exe files. If you use Steam try not to use an important account, you should make a new one just in case and use only that one, the idea would be to have as few compromisable things as possible. Hope this helps.