The second part (with all the question marks) tells the command to use the existing file names up to seven characters, but add '-test' as a suffix, while the asterisk again means apply to any file extension. So, '*.*' means find any file name, with any extension, in this folder. In this command, the asterisk wildcard acts in place of any characters. How about adding a suffix to a group of files? You can do that using the following command: ren *.* ?- test.* Here, the question mark wildcard acts as any character, allowing the command to find any matching files while outputting the renamed files. For example, if you want to change the number of digits in your file names, you can use the following command: ren document?.txt document3?.txt If you want to rename multiple files, you can use the wildcard characters to make changes. The command to rename a single file is: ren filename.jpg newfilename.jpg Type dir and press Enter to see the list of files. Head to the folder containing the files you wish to rename, hit Shift + Right Click, and select Open a command window here.

Bulk rename file