How to change file extension of various files at a time?

I had got a virus in my computer. It changed the file format of many files like jpeg to ocx or jpeg to htt and jpeg to ini.etc.

Now,how can i change these extensions at a time not by changing these one by one?
How to change file extension of various files at a time?
On Windows XP and later versions of Windows, it is possible to rename multiple files at once via Explorer by selecting the files to rename, then pressing the F2 key.



100% free is

The software Ant Renamer : http://www.antp.be/software/renamer/

allows renaming many files and folders with a few clicks.

Its main features:

Change extension

Replacing strings by other

Inserting a string

Move Character

Remove several characters

Enumeration

Creation of names from MP3 Tag (ID v1.1)

Creation of names from the date and time of modification of the file

Random Names

Change case (uppercase, lowercase, first letter of each word in uppercase, ...)

Based on a list of names or a file

Use of images EXIF info

Expressions (regular expressions)











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How to change file extension of various files at a time?
If it changed the file formats, you need conversion programs to convert them back. If it changed extensions, you can just rename the files. (In a command prompt, ren *.ocx *.jpg will rename all ocx files in the directory to jpg.) The file extension *indicates* the file format, it's not the same as the format.



Be careful - if there are real ocx files in the directory, their extensions will also be changed - which you DO NOT want.