Hi Mike,
System Requirements
Windows
* Windows Vista, Windows XP SP2, or Windows Server 2003
* 128 MB RAM (256 MB recommended)
* Dreamweaver CS4, Dreamweaver CS3, Dreamweaver 8
Macintosh
* 500 MHz Power PC G3 processor
* Mac PowerPC or Mac Intel
* MacOS 10.4.x, MacOS 10.5.x
* Dreamweaver CS4, Dreamweaver CS3, Dreamweaver 8
These are the listed system requirements for the CSSMenuWriter.