Install Win7 and Win10 on Bootcamp?

i know may posting in wrong place, can install win7 , win10 (tripleboot) without trashing mbr? if solution possible, please let me know.

sincerely,

sean hawkins

***post moved moderator appropriate forum category.***

its not supported officially; there hacks available, hit , miss. boot camp intended 1 additional instance.

its best keep 1 installation in boot camp , run in virtualbox.

resources:

https://discussions.apple.com/thread/2573748?start=0&tstart=0

http://apple.stackexchange.com/questions/97086/how-can-i-install-both-windows-7-and-windows-8-on-a-mac-mini-2012

additional resources:

Windows / Windows 10 / Install, upgrade, & activate / PC

Traplo