I was troubleshooting a SharePoint environment the other day and one of the issues was where people were trying to create My Sites but whenever they clicked on the ‘My Site’ link a login box appeared prompting them for credentials. Having checked the web application was configured correctly to allow for Self-Service site creation and that the security and authentication providers were not causing any issues in IIS, I was unsure what could be causing the problem. It turned out that the My Site web application did not have an associated site collection. This is odd as when setting up the SSP this is created automatically. To solve the issue I created a new site collection for the My Site web application using the ‘My Site Host’ site collection template. After that, My Sites could be created.