If it's a production server that you're going to install Moodle on then don't use those "all in one" XAMPP packages. It could come back and "haunt" you! - It's better to learn how to install and configure Moodle and your server than to take the easy way out and use an installer that does everything for you but doesn't teach you anything.
And since you already have IIS amd MSSQL it makes sense to use infrastructure too.
Do you have PHP running on that server? if not, that's what you should do first. When it's installed run PHPInfo() and check if the PHP SQL Server driver (sqlsrv or mssql) is correctly configured and that PHP can connect to your MSSQL database. If it can then you're ready to install Moodle.
But before you do that, read the Moodle installation docs first (the links that I posted).
