Windows 10 activation issue

[Shahtaku]

So I took my laptop for repairs and they wiped it, doing a factory reset. Unfortunately they didn't really know what they were doing as they couldn't get my Windows 10 back. So they've put an unactivated version of Windows 7 on it. I bought this laptop for campus in 2016 and it came with windows 8, and a free upgrade to windows 10 (which I used and was running win 10 smoothly). How do I get back to windows 10? 

[#2]

Hi,
it sounds like your activation and product key was tied to your Microsoft account, so chances are if you install Windows 10
https://www.microsoft.com/en-us/software-download/windows10
and sign in with your Microsoft account, it will be automatically activated.
but if it doesn't, please refer to this page:
https://support.microsoft.com/en-us/help/12440/windows-10-activate
https://support.microsoft.com/en-us/help/10738/windows-10-get-help-with-activation-errors