If you are installing SSC and NAV Server on the same computer, it may require as many as five or six reboots of the server. This can increase the time required to install the software. Schedule two to three hours to work through this installation and configuration process.
If you are upgrading from version 7.0, 7.01 or 7.02, I recommend that you first uninstall all Symantec System Center (SSC) and Norton AntiVirus Corporate Edition (NAVCE) software. This is an unofficial step as the software supports an update option, as stated in the main documentation. However during my testing I encountered some strange errors during the update. I found it was easier to uninstall the previous version first. The uninstall step wasn't necessary when upgrading from 7.0 to 7.01 or 7.02. As version 7.5 is a significant upgrade with additional software components, I recommend this uninstallation procedure. You will lose some NAVCE software settings. However this is not much of a disadvantage as you'll still need to go through all the setup options to enable the new features.
If you are installing all three NAVCE server products (SSC, NAV Server, Quarantine Server) on the same system, use the same parent directory. Eg. All software by default installs to "C:\Program Files". This is the recommended installation folder. If you do not have sufficient space on C: drive and you choose to use D: drive, then make sure all installation paths are the same, ie. "D:\Program Files", for all three server products. Do not install across different drives.