HP had sent me some discs to re-install into my laptop a long time ago. I ended up not using them & the laptop is no more. I don’t have the Key or anything. Can I install the Win7 disc in my new HP Win10 pc after a reformat or could it be installed over Win10. Would I be able to register the OS with those discs, do they have a key built in to register the OS? I don’t care for Win 10 so would like to dump it and get back to Win7.