I have an old HP Compaq 3010 desktop computer. The HDD has a dual boot Windows 10 Pro EOS system. The BIOS is legacy. I installed a Kingston SSD on the machine and the original HDD was cloned. I can’t upgrade to the latest version of Windows 10. So I thought I’d reformat the original HDD and do a clean install so that the contents of the dual boot cloned SSD would not change. I cannot disable the second drive in the BIOS. I set HDD first in boot order. My question is briefly whether the Windows 10 installer is smart enough to install the MBR on the selected HDD and not overwrite the GRUB on the second SSD.
Hello again. No windows wouldn’t overwrite the grub on the second SSD, unless you install windows on both hdd/ssd new. Have you tried to do an inplace upgrade on the SSD? If not try this first.
It is quite easy to recreate grub stuff into MBR even if Windows overwrites it.
EndeavourOS wiki has the instructions.
If you set that drive as the bootable drive and install Windows to that drive making sure you check when installing that you have the correct drive it should not affect your other drive.
In the BIOS, I set the hard drive to boot first. I let Windows installer install on the first HDD that I didn’t partition. Everything worked fine, thank you for your answers. So at least you can see the difference between HDD and SSD read / write speeds.