The license depends on the version you have. If you have a corporate version, then there is only a paper license. If you have a boxed product then you will have a license file (randomnumbers.slf). Check for *.slf files on your server and then if you find one or more, open them up with notepad. You will see the expiry dates within the files.
Open up Symantec Anti-Virus and expand the Tree on the left-hand side. Do you see a license sub-folder?
If you don't - then you need to find the paper license / renewal notice. Assuming you don't then you probably have run out!
SAV 9 - well out of date. SAV 10 is about to be retired too. Symantec Endpoint protection is the latest incarnation and you will need at least version 11.0.6 (11 Maintenance Release 6) to get up and running.
There is nothing to stop you re-installing SAV 9 onto another 2003 server if you have the installation CD's, but without the paper license, you are going to be running illegally.
I very much doubt you can download SAV 9.0 from Symantec's servers.