When you select the rename file button in the Select Attachments window, the software displays the File Properties window as shown below:-

File Properties Window
1. Filename - you can edit the filename shown for a file using the filename field. Avoid using colons ":" or forward "/" or backslashes "\" in the name, as the Windows operating system uses these characters to indicate the start and end of a folder name.
2. File Type - the type of file is indicated by the 3 character file extension to the filename. It is not recommended to change the type of file, as the Windows operating system uses this to identify the software to use to open the file.
3. File information - the Original location of the file, the file size and File Modified fields display additional information on the file for your convenience.
4. Cancel - click on the Cancel button to ignore any changes to the filename, and close the File Properties window.
5. Save - click on the Save button to save changes to the filename and close the File Properties window.