will win10 accept a separate hard drive with bootable win7 on it?

In the past few days, win10 seems to have serious issues with that win7 drive plugged into the sata port?
So much so that I wiped the win10 partitions and did fresh install. Prior to the fresh install win10 refused to boot to the desktop if that other win7 drive was plugged in, error was driver stauts filure, we need to collect data type error, over and over or it refused to boot at all.

So I fresh install win10, things seem good, it is activated linked to my ms account. I shut down, plugged in other drive, bios set to boot win10 drive, win10 screen comes up, it shuts down, reboots again, shuts, down, then 3rd boot, it says is installing updates at 100% and pc is very quiet right now, for 20 minutes.

Is this even going to work?

ok it finally came up so it can. subsequent boots are normal speed.