Check to make sure your PC meets the system requirements for Windows 10. 

Processor : minimum 1 gigahertz (GHz).

RAM : minimum 1 gigabyte (GB) for 32-bit

Hard Disk : 16 GB for 32-bit OS 32 GB for 64-bit OS

Graphics card : DirectX 9 or later with WDDM 1.0 driver

Internet Connection : Internet connectivity is necessary to perform updates and to download and take advantage of some features.

1. Select Download tool, and select Run. You need to be an administrator to run this tool.
2. On the License terms page, if you accept the license terms, select Accept.
3. On the What do you want to do? page, select Upgrade this PC now, and then select Next.
4. After downloading and installing, the tool will walk you through how to set up Windows 10 on your PC.
5. All Windows 10 editions are available when you select Windows 10.