I’ve recently moved the database behind DavidOverton.com (also uksbsguy.com) from a Windows Server 2003 system with SQL 2005 to Windows Server 2008 with SQL 2008. This would be the same process if you were potentially performing a migration from SBS 2003 with SQL 2005 to SBS 2008 Premium with SQL 2008 (or SQL 2005, but the performance issue only happens with SQL 2008). The process was amazingly simple: Stop the database on the Windows 2003 system Copy the datafiles, errorlogs, logs etc to the new system Install SQL 2008 on the new system, creating an instance by the same name Modify the registry to point to my new files (details here ) Start SQL 2008 Obviously I had to do some IIS stuff (create a new site) and install and redirect my logging software (WhosOn), but overall it went very well. Or so I thought until I noticed that my normally nominal CPU utilisation had gone bananas. One of the SQL 2008 new and improved features is the Server Activity History which makes it very easy to pinpoint problems...