You need to go into BIOS to change (disable / enable) Secure Boot. 

To do that every time you wish to change OS is a bit onerous. 

Somehow you will need to get the password to do this.

I suggest you make your lesser used system a Virtual Machine and your most used system the Host system.  

Use VMware Workstation Pro to do this. This has always worked best for me.  I have both VMware and Hyper-V (on a different computer).