I use dual boot os with w7 & Ubuntu 16.04 on one laptop 64 bit machine. I use Ubuntu 16.04 & Linux Mint 18.1 dual boot on my older HP 32 bit machine. What I would like to see is the install of a new OS function, read the Hard drive and display options to replace any one of the two OS in a dual boot system. I understand this can be done the hard way if one has much knowledge. But I still would like a simple easy selection menu to do replacement by simply selecting which one to replace during an install of a new OS.

Thank you to all the fine software engineers for the wonderful OS choices.

Respectfully,
pgaboria

You might want to try openSUSE. They have both options, that is the system creates an (often) sensible suggestion for a system layout, but you can also ignore that and do it the "expert way" all by yourself.