PC players use the Xenia Emulator to run backups. Unlike the console, Xenia can often load directly, though extracted XEX files are also supported for better flexibility.
Before you spend hours soldering an RGH chip or hunting for a vintage DVD drive, consider these legal alternatives to downloading full ISOs: Xbox 360 Games Download Iso
That said, here are some methods to legally obtain Xbox 360 games: PC players use the Xenia Emulator to run backups