How to upgrade Windows 8.1 to Windows 10?

[healee]

I had an Acer Aspire E 15 Windows 10 Home system that had problems couldn't be fixed as reported on Screen turns off while the charger is plugged in. and Search on Settings won't work..

I restored to factory settings. The system recovered found to be a Windows 8 system, Version 6.3 Build 9600.

Now how can I upgrade it to Windows 10 Home which I had paid and bought for.

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