Tip: Corrupted and missing files can be replaced with ".rev" files:
What are Recovery Volumes? Recovery Volumes (.rev)
Recovery volumes or .rev files are special files which can be created by WinRAR/RAR and allow the reconstruction of missing and damaged files in a volume set. They can only be used with multivolume archives.
This feature may be useful for backups or, for example, when you posted a multivolume archive to a newsgroup and some of the subscribers did not receive some files. Reposting recovery volumes instead of usual volumes may reduce the total number of files to repost.
Each recovery volume is able to reconstruct one missing RAR volume. For example, if you have 30 volumes and 3 recovery volumes, you are able to reconstruct any 3 missing volumes. If the number of .rev files is less than a number of missing volumes, reconstructing is impossible. The total number of usual and recovery volumes must not exceed 255 and the number of recovery volumes must be less than a number of RAR volumes.
WinRAR reconstructs missing and damaged volumes either when clicking on .rev file, or when using the rc command or automatically, if it cannot locate the next volume and finds the required number of .rev files when unpacking.
You may use the "Recovery volumes" option of the Archive name and parameters dialog or the similar option in the Protect archive command to create recovery volumes. In the command line mode you may do it with -rv switch or rv command.
Original copies of damaged volumes are renamed to *.bad before reconstruction. For example, volname.part03.rar will be renamed to volname.part03.rar.bad.
How to create .rev (recovery volume) files?