Hi
Now navigation error but I can’t your fpt, please check again
You used Magento ver. 1.7.0.2. I think you use new vesion magento 1.9.1. Becase magento 1.7 have errors
You download in
https://www.magentocommerce.com/products/downloads/magento/
Then you extract file download and copy overwite your folder. The end You Index Management and Disable Cache

Thanks
Ngan