If you are using an existing domain with your new hosting account, you will need to update the nameservers to point to the appropriate nameservers.  Upon establishing your web hosting account with FastnetHost.com, you will receive a "New Account Information" email.  This email will have the correct nameservers that you should be using for your domain name.  Each web hosting account can have different nameservers so please be sure to use the nameservers listed in this email.