Thanks Mike.
Yes, I did find all those pages. The problem is that some of the things mentioned didn't work. They only work if your installation is behaving properly. For whatever reason, I only got everything working after cleaning out my Windows registry by hand and completely removing all files. This is something that the Install/Uninstall wizard do not do thoroughly. On this basis it's rather difficult to decide whether this is a problem with the documention or with the installer.
Having read all those pages and found that I need to set old-password for phpMyAdmin to work, I now have to wonder whether that interferes with Query Browser, which refuses to run.
Furthermore, the reference
http://dev.mysql.com/doc/mysql/en/old-client.html just says:
shell> mysql
mysql> SET PASSWORD blah blah blah....
And yet it doesn't remind you of the simple necessity to log in as the root user:
c:> mysql -u root -p
password: ********
mysql>
To try and determine for which reason Query Browser fails to connect requires me to read far too many different pages and collate far too much information. From that point of view, it is very difficult to troubleshoot installation problems.
Michael