Windows 10 just cost me $200, on a new computer. This after a different copy of Windows 10 killed my previous computer motherboard dead during a forced reinstall due to an incompatibility between Windows 7 and Windows 10 (the HD was accessed by Windows 7 on another computer, after still other Windows 10 problems that began the whole debacle.) So that's one computer and $200 that Windows 10 has cost me, lately.