Commercial software development is a complex task that requires a thorough understanding of the architecture of the software system. We analyze the Windows Server 2003 operating system in order to assess the relationship between its software dependences, churn metrics and post-release failures. Our analysis indicates the ability of software dependences and churn metrics to be efficient predictors of post-release failures. Further, we investigate the relationship between the software dependences and churn metrics and their ability to assess failure-proneness probabilities at statistically significant levels.