Once you have installed SQL Server 2012, please do the following:

  • Open up SQL Server Management Studio 2012
  • Connect to the database server
  • Expand the Security > Logins tab
  • Locate the NTAUTHORITY\SYSTEM login
  • Right-click on it and choose Properties
  • On the page that appears, click on the "server roles" tab
  • Check the box next to "sysadmin"
  • Click OK
  • Close SQL Management Studio

You should now be able to install Spira v3.x onto the server.