Solved Windows 8 Recovery problem - partition wrong style

Before I upgraded to W10, I had Macrium produce a nightly clone of 1 TB drive "A" to 1 TB drive "B". When I upgraded A, W10 got cloned to B. However, I discovered that I had lost administrative privileges as a result of the upgrade. During my machinations to gain administrative access, I clubbed B somehow so it no longer boots - A still boots W10. I'm now attempting to go back to W8 on B with a Dell (Inspiron 660) recovery disk, so I can keep a working (but compromised) OS on A.

Thanks to KYHI, I was able to get the OEM product Key using ShowKey, and I'm now past the obstacle of supplying the key when requested. However, I've a new obstacle: Windows Setup is complaining that the partition is of GPT style. This may be a result of something I had to do for Macrium to get it to clone.

I chose the format option for partition 7 (917.5 GB primary), but is still complains that Windows can't be installed on drive 0 partition 7. How should I proceed?

Thanks
Dan

Ah! I was still booting in Legacy mode - I rebooted in UEFI mode, and it appears to be working! I'll report on my progress.

Dan

It was booted into legacy mode... See you figured it out though..

Yes! W8 is installed and running, and M$ updates are now being applied. Many thanks!

Dan