You'll have to explain.
As to W10, if you had it running and activated you can reinstall from USB. If you didn't make your reset and restore key google up the Microsoft Media Creation Kit. No downloading of ISOs etc. It will create a good new W10 USB install key.
so i ****** up badly. Had Windows 10, treid to install windows 7 via USB as i have no working dhavevd room. So middle of install ikke get error, missing parts or something like that. This was after i deleted everything i had on computer. So then i had no os installed and problems installing windows 7. I tried to read up fast, heard something about legacy booting, and then i managed to do the impossible. I clicked in bios, boot - secure boot - windows uefi - key management, inside there i clicked clear secure boot keys. After that i actually managed to get into windows installer last time. There i clicked shift+f10 to get into Chat thing, typed diskpart - select disk 0 - clear - clear all - select disk 2 - clear and another mbr command i think. Now, my computer is ******. I cant Even open the USB installer, it says reboot and select proper device. Am i ******? Asus p9x79 motherboard.