Question:

After I use the program to clean files, when I run MS-Word (Office 2003 Pro), it displays a "Installing Word..." message & seems to be re-installing from the CAB. Does it every time. Is there a file in your list of file extensions that maybe should not be cleaned? 

Answer:

The problem is with file: <Sytem Drive>\Documents and Settings\All Users\Application Data\Microsoft\Office\Data\OPA11.BAK

When Disk Cleaner removes this *.bak file, and one runs Microsoft Word, it triggers some feature re-install of Word. you can set WinUtilities Disk Cleaner to skip that folder or uncheck '*.BAK' category under WinUtilities options dialog to solve this issue.