Dual-boot between W7 and W8.1 or W10?

I bought a new Samsung 512GB 850 Pro SSD to replace the Samsung 256GB 840 Pro SSD but left it in my computer. Which operating system should I put on the old SSD - Windows 8.1 or Windows 10?

 

Well if it was up to me, I would use it to store My Documents on it, Dropbox files....if you need to (want to) have another OS, try Win10. I have been running it since the preview was released and it is pretty stable. It will expire in April.

 

Yeah...try Windows 10, I'm usin' it and it's pretty stable works well.

 

I'm not sure if I want to use Windows 10 because after I install W10, I'm asked to give them phone number (voice or text) or e-mail address that is different from my e-mail address. I'm hearing-impaired and I can't use voice phones. I don't have cell phones that let me send/receive texts. I don't have different e-mail address. Any suggestions?

 

www.gmail.com and create a second email account? Email accounts are free.