Hi had a bsod critical process died code around year and half ago, wasn't using laptop so stored it away. I need to use it now as other laptop has died. After trying to restore Windows using System restore (no go), Startup repair, command prompt (not very tech savvy following suggestions, instructions online) drives are healthy but software corrupted (this happened after windows 10 update) I believe i can use system image recovery with usb drive to restore (don't need any of the files on computer). Will I need to purchase Windows 10 again as the computer came with it preloaded and I can't find a product key. (looking for cheapest option as money is tight at minute). Any suggestions would be much appreciated.