Let me just start out by saying "Do not, I repeat, do not upgrade a Symantec CE AV Server with version 9.01". That is the latest public version visible on the website, but it has a bug that may cause the server to create a duplicate server group. So if you have a server group named SYMCE, you will see a duplicate group named SYMCE (2).
If you have a current subscription (which you better have if you are using Sym CE AV anyhow) call up their support and get the location and passwords to download 9.0.2.
And it's best if you uninstall everything from the server (AMS, SSC, AV, LiveUpdate) and then reinstall from the new version. Of course if you do that and don't have a backup server, you will lose all of your configuration settings, so make sure you have a backup server before you uninstall from one of your Sym CE AV servers.