All I can think of is to change the my user mode to admin level totally, I run DW in a window constantly so I can update the web site whenever I feel like it.
After spending too much time, and trying a number of ideas I ended up finding the solution - for my situation of no preview available for CSS Menu Writer. I uninstalled Dreamweaver completely- using the Dreamweaver application after deactivating DW-CS3, and uninstalled all the extensions.
Then I rebooted (probably not needed, but I like a clean start) and installed Dreamweaver as an Adminstrator. Previously I had installed DW CS3 as a user and simply used the Admin password during the installation period. Now the Preview works properly and I am running as user with Admin privs.
Next to see if I reset my user back to non-Admin privs and see if it works...(pause while I go and reboot computer)...YES I now have Preview as a regular User.
Not sure if I needed to change to Admin privs for the user, but certainly installing DW CS3 as the Administrator appeared to be the main requirement for solving this problem.