Im a linux user trying to update to windows 10 and have a question

I use Mint 15 and do not have dual boot. The laptop I am using had windows 7 on it originally but I no longer have it installed nor did it come with an install disc. I am confused about the upgrade. Do I need to reinstall 7 on my machine to update to ten or is there a way I can upgrade straight to ten which is my preference? thank you for your time.