i have a dell inspiron 3505 ryzen 3 came with activated windows 10 os, i want to install windows 7 os to an external usb drive and use it with this laptop! I need to view and convert some billing datas that are old that supports only windows 7.

So far i managed to add boot option entry that helped detection of usb bootable drive which has os, but the system doesn't start up the setup and skips to loading windows 10!!

Is there a way to install windows 7 on my laptop?