Hi there, I bought a Insipron 15 7000 series laptop with a 6th Gen i5 and a GTX 960m in Nov 2014. I started the laptop, upgraded windows and all the drivers. I did a clean install of windows 10 after this but making a bootable using the Win7 USB tool. after changing the BIOS from UEFI to Legacy, i booted into the bootable, I couldn't chose the primary partition as it wasn't in GPT (or something of that sorts). So i had to delete the entire partiton using CMD in the boot manager. and then installed OS on the new volume created. after booting into desktop, it says windows key not found. what should I do ?