Switch -EP3 - expand paths to full including the drive letter
This switch stores full file paths including the drive letter if used when archiving. Drive separators (colons) are replaced by underscore characters.
If you use -ep3 when extracting, it will change underscores back to colons and create unpacked files in their original folders and disks. If the user also specified a destination path, it will be ignored.
This switch can help to backup several disks to the same archive. For example, you may run:
WinRAR a -ep3 -r backup.rar c:\ d:\ e:\
to create backup and:
WinRAR x -ep3 backup.rar
to restore it.
But be cautious and use -ep3 only if you are sure that extracting archive does not contain any malicious files. In other words, use it if you have created an archive yourself or completely trust its author. This switch allows to overwrite any file in any location on your computer including important system files and should normally be used only for the purpose of backup and restore.