If you want to rename multiple files in the same directory:
- Using the Windows Explorer, select all the files you want to rename
- Press F2 or right click and select Rename
- Enter the prefix for the name you want (e.g. Newname)
- This will automatically rename the rest of the files Newname (1).jpg, Newname (2).jpg etc.
- Make sure you include the extension if you have the Explorer configured to show them.