Service Tag Utility

Is there a location to download the Service tag Utility for laptop and desktop motherboards when we replace motherboards?  Dell sometimes sends a bootable cd, and sometimes they do not.  We would like to be able to create our own bootable cd.  Also, we always use the asset.exe command with the hidden switch of /s to change the service tag since option 3 on the cd they send us usually says the optiplex or latitude we are working on is not supported.  Thanks for any help.