Making Win 10 love its red haired, freckle faced stepsister, Win 7

[Cajun1955]

Let me try this again, as the plot continues to thicken.   So my dependable Win 7 PC just stopped working.  Nothing I tried revived it.  I purchased this HP Compaq Pro 6300 Win 10 PC out of desperation....I needed a working PC.   Now I am desperate to be able to dual boot the thing.   I have two other hard drives: a 1TB internal and a 500GB external.   I also purchased a never opened Win 7 OEM installation disc.   I have been trying, literally for weeks now, to MAKE Win 10 accept and ALLOW Win 7 to be installed, then to operate from its own dedicated HDD.

NOTHING!   

Nothing I have tried, nothing I have read, no video I have watched has explaind WHY Win 10 WILL NOT ALLOW WIN 7 TO BE INSTALLED, TO WORK!!!

The BIOS speaks of your normal legacy storage devices AND makes a passing reference to UFEI as well.

I have tried installing Win 7 from the DVD with UFEI active.  Nothing

I have tried installing Win 7 from the DVD with UFEI inactivated (as far as I can tell).  Nothing.

Sometimes installation will begin only to stop and to be told that Windows cannot install to that drive because of X, Y, and Z.

Sometimes installation wll not even begin and I'll be told there is no OS.

Sometimes installation begins and stops when I'm told I need to find and install drivers.

I AM AT MY WITS END!

I am thoroughly convinced, at this point, and on line postings seem to bear out my suspicions, that Win 10 and its AI components are actually monitoring my attempts are restoring Win 7 and are purposefully mutating the Win 10 environment to stop me in my tracks everytime.

Yes, other people have complained of such OS interference, around Win 10 operation, and have raised the same issues and suspicions.

So, ANY THOUGHTS, ANY IDEAS, ANY SUGGESTIONS?

[WAWood]

I don't quite understand what you are trying to do.

It sounds like you have two drives and you want one windows on one of the drives and the other windows on the other drive.

This is a simple process but your description has some confusing points.

It appears on want on OS to be on an internal drive and the other OS on an external deive.  This can not be done,  Windows has to be installed and run from internal drives.

it also appears you are trying to install one OS while running another OS,  This can also not be done,  You have to boot the machine using the install media and run from that.