SP2010: Obscure settings that might have a great impact on SharePoint 2010: will be a series of short to medium lenght articles about quite obscure settings that might have an impact on SharePoint 2010 server health, stability and performance.
As every SharePoint administrator should know, as soon as you install SharePoint on your machines, the IIS default web site is shown in a stopped state in IIS. And that as is good thing I want to add.
A problem on the organizational side I encountered is that sometimes when SharePoint has a problem the guy tasked with fixing it doesn't know about the logic of SharePoint. SharePoint isn't working? I see a stopped site in IIS? (I guess you know what I mean by now). If the default web site is accidentially started, a lot of things may happen, but whatever it is, it is not good for your SharePoint health :-). Therefore I recommend deleting the default web site (you don't need it in SharePoint anyway and if you ever uninstall SharePoin you can always reinstall the IIS role). If deleting the default web site is no option for you, at least tell everybody that might be tasked with fixing a SharePoint problem to never, ever start this site.