Bulk renaming utility is a software for Windows which would let you rename files, change file extension and file attributes in bulk.  It can do this according to the critieria that you specify, for example you might want to rename a file such that its name starts with the date when the file was created. Another cool thing is you can name the files from data contained in EXIF tags from your digital camera pictures or ID3 tags of your mp3s.

You can also use this tool to change the creation and modification time stamps of files. This is a must have tool in your systems administrator's toolchest!

More info and free download available at http://www.bulkrenameutility.co.uk/Main_Intro.php