Hello,
I know that this utility was once requested in the past on the forums, but the developer has only recently made a proper portable "No Installer" version of the software (As well as updating to v 3.0.0.0). I packaged it myself locally, but would love to see it added to the official list.
Download:
http://www.bulkrenameutility.co.uk/Download.php
Site:
www.bulkrenameutility.co.uk
License/Info:
TGRMN Software
Freeware. Not open source. Not allowed for commercial use without a license
version 3.0.0.0