Recently Ive been doing a number of demos of SMS 2003 and MOM 2005. I had to set up an environment to do it though in my lab which has 6 HP DL380 G4 Proliants, 3 of which run Virtual Server 2005 and have dual hyperthreaded proc's with 6GB RAM. I wanted to make sure that the images I have were kept up to date and fully monitored, so I built a system and demo'd it to people..:)
I found in my server build that the install for SMS 2003 isnt quite as slick as Exchange 2003 - if Exchange doesnt have the required pre-requisites it stops the install process. SMS 2003 just installs and then you need to work out why its not working right....:) So to get it working right make sure you do the following as a set of very basic prerequisite steps...more documentation is on the Product Documentation website or in the SMS 2003 help as part of the install.
This gets you to a point where you can complete the install without major errors.
Next make sure that accounts you are installing with have appropriate permissions to complete install and be able to extend the schema in Active Directory.
Go ahead and do the install. Make sure you check for errors in the Error Log and System Status/Site Status area of the SMS Administrator Console. You should be able to start switching on the individual components of SMS such as the Management Point, Reporting etc and enabling the BITS functions of the Distribution Point now because of the prerequisites being met. Oh and install SMS 2003 SP1!