In this post, I am going to explain how you can reinstall your Umbraco database, so you can start from scratch.  There are a number of scenarios when this is really useful.  Building a new website can often involve a lot of trial and error of approaches until we find the best one that meets the client's needs.  In this process of experimentation, it's very easy to break a database, add unneeded document types etc..  If you use a package like uSync you can delete everything, and rebuild your website really quickly. Reinstalling your Umbraco website is surprisingly easy.  Just to note, I'm going to assume that you are using SQL manager in this process.  In your SQL database, create a blank database and name it whatever you want. In your web.config file, clear out your connection string settings, so it looks like this:

You will also need to clear your umbracoConfigurationStatus within Umbraco 8 AppSettings, like so:

Or Within Umbraco 7, like so:

After making these changes, if you try to load Umbraco again, you should now be presented with the installation screen again.