Hello. I am not very experienced with software and different programs on computers but I came here to ask this question. So recently, I retrieved an old IMac (2007) that was sitting in my shed for a while. Me and my uncle wiped the hard drive and were trying to reinstall a fresh copy of mac os El Capitan. We tried the feature in the reset IMac where it would allow you to reinstall El Capitan but every time we tried we encountered an error message. I then downloaded mac os tiger and converted it to a .iso file and formatted my usb to FAT32. I would then put this usb in to the imac and run the boot menu but it never appeared on the screen. I have been trying to use many different programs like PowerISO and ISOtoUsb and UUByte Iso Editor but to no prevail. (FYI, i am using all these programs on Windows 10 using a 16gb usb stick.) I was wondering if any of you had answers to this problem.