My Advice: Before you open the email to click on link to accept the Friend. First contact them the ordinary way, phone, text, email, talk in person to make sure that it is them that has made the request. Spoof (full of viruses and malware)'friend' requests on Facebook are very common and the link in the email may not be what you think it is. I would suggest caution and to resist the urge to accept every request in your email inbox.
How to get Windows 10 now: how to download and install Windows 10 even if GWX.exe is missing