windows7 installed on two drives--but boots only when both are plugged in

[rompersuncle]

i have 3 ssds, plugged into sata ports 1, 2, and 3. when i ordered the machine, windows 7 was installed to the drive on sata port 1 (P1); shortly after that, my boss's machine crashed, so i gave her this one, and put her system on P2 using acronis. P3 is a spare drive used for backups etc.

To summarise
P1 - original Win 7 install
P2 - second/current Win 7 install via Acronis
P3 - spare
(the m/b is an asus gryphon z87 with ami bios --recent version).

The problem is that i need to boot one time from the original P1 install to deactivate some software so it can be moved to another machine.

i thought just unplugging sata cables P2 and P3 would get P1 to boot, but when i try that i get 'boot selection failed because a required device is inaccessible' (0xc000000e); plugging in only P2 gets the message 'BOOTMGR is missing'.

But whenever both P1 and P2 are plugged in, it boots the install on P2--assuming the bios order is set to P1 before P2. Does this make sense to anyone?

If so, any suggestions on how to boot from P1 and then get it to go back to P2 when I'm done ... without reinstalling?

thanks,
Rick

 

[USAFRet]

1. You probably can't use the Windows installed on P1 and move that to a whole other PC. Windows often chokes when it sees new hardware.

2. The boot manager lives on one drive. P1 in this case. Unplugging that = no boot for you.

Solution:
Save all the relevant data on P3.
Put whatever drives into whichever PC will be their actual home.
Install the OS and applications.

 

[rompersuncle]

Thanks.
I dont need to move drives. I just want to boot P1 and deactivate some software so i can activate it (the software) on another machine.