They are the uninstall files for the Service Packs. They can be deleted, if
you are *sure* that you will not want to uninstall the Service Packs at any
time.
Adding to Will, this page will give more information (if you've installed
SP2 and want to clean-up the folders)
Tidying up after installing SP2: http://forum.aumha.org/viewtopic.php?t=7265