I recently got this pc and put a windows 10 HDD in it, it booted fine and all but later I wanted to install linux on my second HDD, I made a bootable usb stick and went to the bios to change it to boot first and I noticed it was in legacy mode , I did not care till I cant get the usb stick to boot and once I changed it to UEFI mode I see no options so I try to add some but it gave me the "FILE SYSTEM NOT FOUND" error . So I did some tutorial on how to fix it but none work.