Repairing a damaged ISO

In addition to resuming a download, Bittorrent can repair a damaged portion of a file by redownloading only that segment of the file. The hash check bittorrent does when you resume a file download rechecks the integrety of each small "chunk" of the file. If a "chunk" fails the hash check it is redownloaded. You can actually use this tool to fix files that have been downloaded with other methods, but that fail the MD5SUM check. Just start a fresh bittorent download, then stop and exit bittorrent. Next replace the just started download file with the complete but damaged one, renaming the file if necessary. Restart bittorrent and the hash checker will verify each "chunk" of the file, redownloading what is necessary. I prefer bittorent instead of FTP for this reason.