Microsoft has said that it will have "mainstream support" for Windows 10 until October 13, 2020 while "extended support" until October 14, 2025. The five-year mainstream support and ten-year support is similar to the support cycles that Windows Vista, 7 and 8 had.
But, what if your computer is no longer supported by its manufacturer? That's OK, as you'll be able to install Windows 10 "even on devices where the OEM does not officially support Windows 10 and has no plans to do so" according to ZDNet's Ed Bott. So even if your PC manufacturer no longer offers you support, Microsoft will continue pushing out security updates to your Windows 10-powered PC.
With the release of Windows 10 arriving next week, it's good to hear that Microsoft has your back when it comes to support with Windows 10.