Something to watch out for when installing SIMMS or even just sql2008 on its own.
Sometimes when installing sql2008 on a computer that had sql2005 there are errors due to a conflict, if you were to try to install manually you would see the following error: "The SQL Server 2005 Express Tools are installed. To continue, remove the SQL Server 2005 Express Tools." or when installing SIMMS using the automated installer the installation just fails when installing SQL.
Any computer that had sql2005 installed or still has sql2005 installed
When installing SQL2008 you may get the following error: "The SQL Server 2005 Express Tools are installed. To continue, remove the SQL Server 2005 Express Tools." or when installing SIMMS using the automated installer the installation just fails when installing SQL.
Per the following article: http://social.msdn.microsoft.com/Forums/en-US/sqlsetupandupgrade/thread/5fc58507-9f40-4213-acbd-32a57c8822d7/
BEFORE launching the SIMMS installer on systems that have had or still has sql2005 installed, rename the registry key at: HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\90 to HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\90-old per the article mentioned and it seems to work well
SQL2008, The SQL Server 2005 Express Tools are installed. To continue, remove the SQL Server 2005 Express Tools.