Understand the hardware requirements for Windows 10

If you want to upgrade to Windows 10 from your current operating system, your computer probably won’t complain. Windows 10 should run without problems on any PC currently running Windows 7, 8, or 8.1. (Actually, the upgrade is free.)
If your computer is running Windows Vista or Windows XP, Windows 10 may still run, but it’s not good and upgrading is not recommended.
If you have a tech expert in your family, ask them to translate the following table, which shows the Windows 10 hardware requirements you can find written in fine print for new PCs.
Windows 10 hardware requirements
Architecture                     x86 (32-bit)                                                                                                  x86 (64-bit)
Processor                       1 GHz or faster
Memory (RAM)            At least 1 GB                                                                                                       At least 2 GB
Graphics Card              DirectX 9 graphics device with Windows Display Driver Model
(WDDM) Driver
HDD Free Space            16 GB
Firmware                    Unified Extensible Firmware Interface (UEFI) 2.3.1 with Lock
enabled boot
In common parlance, the table simply states that any PC sold in the past five years can be upgraded to Windows 10 with little to no problems.

Windows 10 runs almost any program that works on Windows Vista, Windows 7, Windows 8, and Windows 8.1. It even runs some Windows XP programs as well. However, some older programs, including most security-based programs, such as antivirus, firewall, and security suites, will not work. You will need to contact the software manufacturer for an upgraded version.
Don’t know what version of Windows is running on your current PC? If clicking the Start button brings up the Start menu, right-click the Computer entry in the menu, and choose Properties. The screen that appears lists your version of Windows.
If there is no Start button, you are running Windows 8. If clicking the Start button fills the screen with a set of colored squares, you are running Windows 8.1.