My problem may have been that I have AVG 8.0 installed so I did a rootkit scan.

It claims that D:\addon\Fonts\XaraFonts.exe has an infection.

D: is my CD of course so removing this from the CD is not very possible!

Anyway after a number of restarts and new downloads, Webstyle eventually installed itself from the downloaded version including the DW extension (I have an ancient copy) which for some reason also includes links to WebStyle 3 and Menumaker, neither of which I have or need (I believe MenuMaker and presumably WS3 are included in WS4) and ScreenMaker which I don't particularly need so will remove it.

I don't think it had anything to do with AVG as it is still running, firewall included.

But whatever it was that made it difficult to install, it was still messy. I presume the downloaded version will not clock out in 15 days - it hasn't asked for me to enter the serial number again...

So now to try an run it!