I'm currently dual booting win7 and Kali 2016 (I think I'm on 2016.2)
System is rock solid stable, I stared with Kali 2016, then did rolling upgrades, all was fine. But I haven't upgraded in over 6 months. Curious if its 100% safe to do rolling upgrade to kali 2017? I mean, worst case scenario, my Kali doesn't work that's okay, but is there a chance it will mess up my grub2 and ability to get to win7?

Just curious before I try it, don't wanna risk losing windows, If I gotta risk it, i'll just take hte time and wipe my whole laptop (thinking of swtiching to UEFI anyways so I can triple boot win 10)