WampServer

I needed to upgrade Wamp2 to PHP 5.3 to find some issues on the clients server. I had various errors,
The configuration file containsa syntax error on line 831:
[EParseError] Invalid section tag
because the lines were not ending correctly. Eventually, I decided to do a fresh install, so I renamed the wamp folder, and re-installed from scratch.

Now I can't get Virtual Hosting back. I have cut away most of the sites to simpify for myself, so I am trying to get just one site working. In httpd-vhosts.conf, I have

#<Directory C:/develop4>
# Order Deny, Allow
# Allow from all
#</Directory>

#<Directory C:/wamp/www>
# Order Deny, Allow
# Allow from all
#</Directory>

NameVirtualHost *:80


<VirtualHost *:80>
ServerName devsite
DocumentRoot C:/develop4/devsite
</VirtualHost>

If I # out both of the two top paragraphs, C:/develop4 and C:/wamp/www,as shown above, I get
Forbidden
You don't have permission to access / on this server.
for both [devsite] and [localhost]

If I take out the all the #s, I get
Firefox can't establish a connection to the server at localhost.
for both.

If I # the line in httpd.conf
# Virtual hosts
Include conf/extra/httpd-vhosts.conf
then [devsite] and [localhost] both show the localhost page.

Can anyone see what I have missed?