Hi,
Since you already had Windows 10 installed you can install it again for free. You do not need a product key and if asked during installation just click on "do not have product key". Once installed and connected to internet Win 10 will automatically activate as long as you install the same edition you had on the PC before (Pro or Home).
Now download the media creation tool from Microsoft and once downloaded run as Administrator. In the Window that follows choose upgrade this PC now and follow the various Windows until installed.
https://www.microsoft.com/en-us/software-download/windows10
When installed Win 10 will also update all drivers.
If you need further help, please let me know,
David