You might have read an earlier blog entry about my problems to remove a Data Collector (DC) information in SQL Server 2008. I still haven't found any info on how to do this, but my questions in the MVP group triggered some activity.
Bob Ward looked into how to rebuild the system databases. This was on my list to try (after removing DC config and if that didn't work rebuilding msdb). But Books Online had very little information on how to actually do the rebuild. Since there were quite many changes in setup between 2005 and 2008, I didn't feel like trial and error based on how we did this in 2005.
Bob helped me out with some information on how to do the rebuild and it is very easy! I now have a bat file which does rebuild of three instances - and it only takes 5 minutes. And even better: no installation media is required - and it also remembers the collation for my system databases!
Enough said. Check out Bob's blog post at: http://blogs.msdn.com/psssql/archive/2008/08/29/how-to-rebuild-system-databases-in-sql-server-2008.aspx