Thanks so much for all the comments and suggestions in my WYSIWYG web design thread. I'm asking this question separately so it doesn't get lost in that continuing discussion.
As a break from evaluating drag-and-drop type editors, I took another look at the raw code for my site, using Notepad++ . This has a handy "Run" option which opens files in a browser of your choice, but it only generates the results of the particular single file that's being edited - so if I'm working on index.php for example, all you see in the preview is what's coded in that file, without all the other elements added by others (background, headings, menu and so on).
Is there a way of previewing my entire site offline? Many thanks.