The .chm help in the portable version will not work unless..

[Admin]

If you download the Bulk Rename Utility No-Installer Version (BRU_NoInstall.ZIP) and then extract all files to a folder, the .chm help file will not work unless you unblock it first.
This is a Windows security feature : https://stackoverflow.com/questions/4400744/chm-viewer-unable-to-show-contents

To unblock it:
- Right Click on "Bulk Rename Utility.chm"
- Select Properties
- Select the checkbox at the bottom of the file properties window to unblock file that came from another computer