Please find the details below already addressed the issue.
In your case you have not installed SQL Server prior to install NCM
We do not ship SQL Server when you download Full version of software .
Please Note SQL Express edition only embedded when you have downloaded "Evaluation Version" of software
Currently you have downloaded FULL version from "Customer portal" therefor SQL Server will not be installed during the installation process.
Now You will have to install SQL Server prior to install SolarWinds NCM.
Following post have all the required download links available and instruction required during installation.
SQL SERVER – 2008 – Step By Step Installation Guide With Images
Please find the details below i have also included installation videos for you which will guide you through the process .
Network Configuration Manager 7.x Standalone Installation