RENAME--Examples Suppose you want to change the extensions of all the filenames in the current directory that have the extension .TXT; for example, suppose you want to change the .TXT extensions to .DOC extensions. To make this change, type the following command: ren *.txt *.doc To rename a file named CHAP10 (on drive B) to PART10, type the following command: ren b:chap10 part10 The newly renamed file PART10 remains on drive B.