So, you have two problems !
First, you need to download wampserver2.0i.exe before trying to install the addon.
Then, wamp does not need any password, so you probably have IIS (webserver packaged in windows) installed.
So you won't be able to use wamp unless you uninstall this application...
Florian
WampServer Patch (
Screenshots)
Topic EN :
www.wampserver.comTopic FR :
www.wampserver.com