switching boot drive WITHOUT bios access?

[callumcampbell15]

Hi. I've recently managed to get windows 10 installed on my mac pro, with a lot of hassle; along side OSX Sierra. I currently have an unflashed GPU, a GTX 980, which means I can't view the boot loader in order to change OS's. I need to know if there's a way (like in OSX), where you can change the boot drive from within windows itself? The only way i know how to do this is unfortunately through the bios.

 

[Colif]

I don't know if this works as never tried it

Go to settings/update & security/recovery
under Advanced startup, click restart now
choose Use a Device

Now if you can boot from another hdd in the PC, that would be my guess as to where you do it as PC should boot from whatever you choose here. I don't know if it shows other hdd though. I suspect it won't though: https://www.lifewire.com/advanced-startup-options-2625805

 

[jojesa]

Hi. I've recently managed to get windows 10 installed on my mac pro, with a lot of hassle; along side OSX Sierra. I currently have an unflashed GPU, a GTX 980, which means I can't view the boot loader in order to change OS's. I need to know if there's a way (like in OSX), where you can change the boot drive from within windows itself? The only way i know how to do this is unfortunately through the bios.

You won't be able to change withing Windows unless you edit the Boot Manger, which is not a good idea.
If you install each OS in a separate drive, then you could switch between both OSes by selecting a different drive every time you boot without the need to get into the BIOS.
If you use the save drive you could use Windows Boot Manager menu to select the OS when you start your computer without getting into the BIOS.