The error "SQL Server does not exist or access denied" occurs when Booking Pro is unable to connect to the instance of SQL Server hosting the Booking Pro database. There are quite a number of  reasons why this might happen and a comprehensive list is available on Microsoft's web site by clicking here. This is long document listing many potential causes but fortunately a significant proportion of the instances when this error occurs can be resolved by checking the following on the PC hosting the SQL Server database used by Booking Pro. The name of this PC is shown on the Booking Pro's Welcome page and will look something like the following: "\\PCname\Instancename\Databasename" (e.g. \\PC001\BPRSolutions\BookingPro).

Is a firewall blocking access to the instance of SQL Server used by Booking Pro?

Logon to the PC used to host Booking Pro's SQL database (i.e. \\PCname) and try signing onto Booking Pro. If don't get the error then the most likely cause is that a firewall is preventing access to SQL Server from workstations. To overcome this reconfigure your firewall to enable access on UDP port 1434.

Is Booking Pro's SQL Server installed correctly?

If you still get the error when logged onto the PC hosting the SQL database (i.e. \\PCname) then you will need to check to ensure that SQL Server is installed correctly. To do this please check the following:

1. Open the Services applet in the Administrative Tools in the Control Panel.
2. Examine the list of services.
3. If there isn't a service called SQL Server (Instancename)" (e.g. SQL Server (BPRSolutions)) then the database isn't installed on the machine and you will need to install it by installing the Database Components from your Booking Pro Setup CD.
4. If the service is present make sure that the service is showing as "Started" and that the "Startup Type" is set to "Automatic" and if necessary start it. If the service fails to start then check the Event Log (Control Panel->Administrative Tools) to determine why it hasn't started and

If after checking the above you still get the error then you will need to work your way through the full list of potential causes found here.