I had exactly the same problem as this - "The requested URL /My Joomla/My Joomla/index.php was not found on this server" with my site url appearing twice.
Purging various caches and fiddling with htaccess / SEF / and lots of other suggested fixes didn't cure the problem.
I eventually shut down my laptop completely (cold re-boot) and the problem magically vanished! I suspect that simply restarting all the WAMP services would probably have cured the problem also.
Perhaps you could add this tip to the 'Help us to help you' advice page for developers working with WAMP on their localhost.
Last edit: 13 years 6 months ago by philiplardner.
The solution is simple
You have My Joomla/.... you have a blank, it's a big mistake, your diretory will be named My_Joomla fot example...
It's not a problem with joomla or Cb.