Microsoft so very graciously provides a free version of SQL 2005, SQL Express, with MOSS. If you install MOSS using the Basic option or Single Server under Advanced you get SQL Express automatically. So what if as a budding newbie SharePoint admin you chose the Basic option, but now as a wise aged SharePoint admin you've seen the error of your ways and want to use a more respectable version of SQL for your SharePoint backend? You're in luck. In this blog post I'll walk you through upgrading SQL Express to SQL Standard or Enterprise.
First thing you need to do is get a copy of SQL 2005 Standard or Enterprise. Which version you choose depends on the redundancy and availability you want. Either will upgrade from Express. After you have your media you can start the install. This step is important as you have to pass the setup program a parameter to let it know you're doing an upgrade. To upgrade use the command setup.exe SKUUPGRADE=1. It should look like this:
That's all there is to it. Once you are using full SQL you have quite a few more options available to you like log shipping, database replication, SQL Profiler and more. If you have any questions about how to leverage those tools with SharePoint, leave me a comment and let me know.