Well there is a way if you dont care about the reports, instances and folders you had in your enterprise system.
GO to "Crystal Configuration Manager" CCM,
Coniguration tab and select the SPECIFY button for CMS datasource and choose the oprion "Initialize the APS database" This will re-format your APS database, ie it changes everything, it will jus keep you 2 users "Administrator" with NULL passwd and GUEST without password, and whatever is default while you had installed CE.