Be sure to follow the guide: http://www.yiiframework.com/doc/guide/1.1/en/topics.url
One thing I was missing is that you need to make sure when modifying the rewrite rules that you have the following specified for either your virtual host or in the apache conf file:
AllowOverride All
Yours might look like:
<Directory “C:/Development/Workspace_Juno/ErplyWeb”>
AllowOverride All
Order Allow,Deny
Allow from all
Options +Indexes
</Directory>