I Stumbled on a software which can rename all your files in one go- File renamer. This is helpful if you have lot of pictures taken with Digital Camera. Cameras often name the pictures starting with DSC or P or some other letters followed by numbers. When you copy all these files to your hard disk, these names does not make any sense. You can rename all these files with the name you want followed by the incremental number.
To use the program at its simplest just select the file(s) you want to rename, enter the new name you want to use and press the Rename button. All the selected files will be renamed using the entered text followed by a sequential number. The file extension is not changed. There are options in case duplicate files are found and also to move all the files to new directory.
File Renamer is a released as a freeware.