well, in reality, installing the power store on your local computer is not really going to do much for getting the store up and running live.
To get the store up and running live, you should go through the installation on your remote server.
Upload the power store file to your remote web site host, then run the installation.
as for the problems you are having locally, it does sound like something has gone pear shaped in your xampp installation, you may be able to fix it by uninstalling xampp and reinstalling it.