YSK if you’re still using an old version of Windows, that you can STILL upgrade to Windows 10 for free, legitimately, through Microsoft, and probably should do so before 11 is released.
from /r/YouShouldKnow
如果你還在使用舊版本的Windows，你仍然可以通過微軟免費、合法地升級到Windows 10，並且可能應該在11發佈前這樣做。