Whenever you had problem in your magento installation and when you feel your magento website behaves differently, you might be thinking to resinstall the magento completly. For this your first thought process will be take a backup of the old files in your local and work with it or upload new files, like this many cases, you want to repeat the installation on the same server, it is not necessary to download the files , downloading the files takes lot of time based on your internet speed, magento has an easy reinstallation process.
To reinstall the magento, follow below steps,
Step-1: On the server,
delete the file: app/etc/local.xml
Step-2: Delete any files and directories found in:
Step-3: With your browser, navigate to your Magento directory.
For example: http://www.yourDomain.com/magento-directory
The Magento Installation Wizard launches automatically.
If you plan to develop your store over a period of time, we recommend that you set up a staging environment where you can test changes before applying them to the live store.
A staging environment is just like any other Magento CE installation, but is not accessible to the public. You can use a version control tool to keep files synchronized between the staging environment and the live store. We highly recommend that you use a staging environment to test extensions and before updating your live store to a new version of Magento CE.