Andy,
The SL500 leaves the factory requiring an activation code. It is a very long upper/lower case/numberic string which will generate the admin and CE logons, and allow the machine to come out of vegetable state.
The online form to do this IS on the CRC, but only the employee logon section, so you will need to contact Sun. If you got the machine from a broker/reseller then then they should get it for you, as I am sure you need a six digit site location number (which you likely won't have). You will also need to quote the serial number.
PS: If its 2005 and never used then it will have early firmware. Don't try to update it or you will wipe the logons and it will need activated AGAIN.
regards,
STKman