and to top it all off, with this last system I provided you, if you ever wanted to upgrade the CPU on it you literally just have to get the new CPU, whether it be a higher end Ryzen chip from this generation or one of the new chips that are coming out soon using the new Zen2 architecture. And it'll still be overclockable. You can even put a 1080ti in this build and it'll run because that power supply will handle it. you aren't guaranteed to get a good PSU with the pre built systems. and the system you linked doens't have an SSD and isn't overclockable on the CPU. the only thing that PC you linked has that this one doesn't is built in wifi adapter. that's it. You don't need to buy windows to use windows. all activating it does is remove a watermark in the corner (which doesn't always happen to be present) and let you customize the colors of your window boarders and the task bar. you can still get a wallpaper by right clicking the image you want to use and selecting the option for making it the wallpaper. you can get windows and install and use it fully for free directly from microsoft. all you have to have is a PC and a flash drive with 8gb or more of space and just download and use the Windows Media Creation Tool from Microsoft to make a bootable flash drive that you can use to install windows on any PC.