Norton Backup would not install because it triggered two Trojan horse warnings from Norton Internet Security 2010. The firewall and SONAR function has to be disabled in order to complete the installation. However, once the product was installed, these functions could be not restored to full function. Norton Internet Security was disabled by your own product.
Worse, one Norton backup began to run, it took over all the processing power and memory of the PC. It was un-usable. After a cold boot, I was able to uninstall it.
Once Norton Backup was uninstalled, Norton Internet Security began to operate properly again. Also, the performance of the PC returned to normal.
This was a very unhappy experience for me.