Original Xbox games vary in size, but most are between 500MB and 4.7GB. If a file is only a few megabytes, it’s likely a scam or a virus.

Files like .cso or zipped archives to save storage space. Why Seek a Full Archive?

The Ultimate Guide to Xbox ROMs and ISO Archives: Building Your Digital Library

You will need the Xbox MCPX boot ROM and the Flash ROM (BIOS).

Files already extracted and ready to be dropped directly onto an original Xbox hard drive.