Hi,
Do you install SEP manager or SEP client? If it is the SEPM than do you use Vista 64-bit or 32-bit? If it is 64-bit, it is not supported as platform for SEP Manager.
If you are installing just SEP client, then you should pay attention to port 80 (http) for heartbit to SEP Manager and port 8443 (https) for content and product updates and policy update.
To access the SEP Manager, after you installed it, go to the browser and go to the
http://dress of SEP Manager computer>:9090 (in case you use default values).
Best regards,
Vladimir