HTTP 404 Not Found after a "successful installation"

I was able to get through all the steps needed to install OpenCart but when I clicked the "Online Shop" button after successuflly installing I get a HTTP 404 Not Found error. URL is http://localhost/opencart/index.php. Browsing to the admin site, http://localhost/opencart/admin/index.php, I get "Server Error in Application "DEFAULT WEB SITE". I am doing this on my local machine for testing and to get familiar with everything before installing on a server. The MySQL db was populated and am using PHP 5.2.6.

Both config.php files, one under the admin folder and under the root folder, both have nothing in them before and after installation?? That seems weird. The install folder has been removed. The site is in IIS because I placed all the files from the upload folder under inetpub/wwwroot/opencart and browsing to localhost/opencart/install/index.php allowed me to go through the install process.

Thanks in advance.

trg getting rid of the php.ini and .htaccess

I removed the .htaccess and both php.ini files and still receive the 404 and Default web site errors. I even went through the install process again with the files removed. DB was re-populated and config files are still empty.