Dual Boot Win7/Win10 (demo)

[41donwb41]

I have tried to do this.
Win 7 on internal HD on an MBR partition.
Win 10 demo on different internal HD with GUID partition (GPT).
On boot up there is no choice of OS to boot.
PC boots straight to to the newly installed Win 10 demo. It works normally.
If I go into the BIOS boot sequence and inhibit Windows Boot Manager (the 1st item in the sequence)
then I do get a choice on boot up.
The Win 7 option boots OK.
But if I select Win 10 option, then I get a message saying the selection is not recognised, or can't be found or is corrupted.
The next boot sequence options after the disabled Win Boor Manager are the 2 HDs carrying Win 7 & Win 10.
In MSCONFIG the 2 OSs are shown with Win 7 as default.
I can't put Win 10 on the same drive as 7 because the win 10 installation seems to require a GUID partition.

What am I doing wrong. Any help would be appreciated.

 

[jefboyardee]

All I know is that I installed W10 on a separate NTFS partition of my main hard drive, W7HP on another, and the choice does come up. So I guess it's them being on separate drives?

 

[41donwb41]

Many thanks for the input. That's the conclusion I've come to as well.