Hi, I had a dual boot Windows 7x64 Ultimate and Windows 8.1 retail on the same SSD. Windows 7 activated with DAZ loader. Problem: I upgraded Windows 8.1 retail to Windows 10 Pro. All goes well but today I receive a warning from W7 Ultimate to validate my Windows. I think (not sure) that the Windows 10 install messed up the bootloader ? What can I do ? I don't want to kill my Windows 7 where I have a lot of stuff. Thanks for any advice.