Hi, welcome.
I am not sure that SQL Express is an option, I just know the full Microsoft SQL Server works. Any way, with a little Googling I gather that you’re not the first to try it, so let’s assume it’s possible.
If you don’t have a strict requirement to use the MS database I would advise you to switch to MySQL or MariaDB, even if you stick to the Windows server. These configurations are far more tested with SuiteCRM and it will probably save you some hassles.
If not, please tell me more specifically what you’re putting into each field in the installer.
If you’re using a name, not an IP, check that you have DNS resolution working for that name.