When deleting the raw files from the software, the raw data files will be removed from the disk as well. In this case you can most probably recover the files by copying them back from the "Backups" folder under the project root to the "RawData" folder.
When you deleted the files in Windows Explorer, you can restore the files from the "Recycle Bin", except when you choose to delete the files permanently (holding shift while deleting the files).
When you cannot recover the files using the ways described above, it is also possible to copy the raw data files from the "Modified" folder to the "RawData" folder, but you will get the processed rawdata to show on the map and you will not be able to revert back to the original recorded data.
