I recently tried to install Windows 10 to my computer. Before the install, I had a Windows 7 and Ubuntu Linux dual boot with 3 drives: SSD for Linux boot drive, 2TB mechanical for Linux home folder, and 500Gb mechanical for Windows 10. I told Windows 10 to reformat the 500Gb hard drive and then install to there. The Windows 10 installation failed with error 0x80070002 (typed from memory, although, the googling results for that error code seem to match those of before [it is a Windows Update error, so, I am unsure how that could affect the the installation of Windows beyond failed updates, in which case the system should still be usable and my hard drive should still "exist"]). When I re-tried the Windows 10 installation after a reboot, the 500Gb mechanical drive was missing. A Linux Mint live CD was also unable to detect it via GParted. It did show up in the BIOS as a boot option, which, upon selection, simply provides a blank screen with a blinking command prompt cursor.
NOTE: A Windows 7 key was used to activate the Windows 10 installer, but, it was accepted as it should be (for that Windows 7 to Windows 10 upgrade process was initiated but was unable to finish before the expiration of hte free upgrade offer). NOTE 2: I would, of course, like to get Windows 10 working. But, at this point, simply getting my hard drive back would be an acceptable option as well.