Hi. I noticed this problem on one of my computers shortly after I first installed Norton Security on the 25th of last month. Now it’s happening on two of them so I know something is up. I leave my computers on 24/7. The performance usage graph (CPU usage and system usage) goes blank with long term use. The only way to get them working again is to restart the computer. I did try a reinstall of NS on one of them but the graph keeps going blank. Both are desktop computers. One is HP Pavilion Elite with i7-2600 @ 3.4 GHz, 12 GB RAM, AMD Radeon HD 7570 with 1 GB and a 2 TB Western Digital Black HDD. The other is an HP Pavilion with i7-2600s @ 2.8 GHz, 8 GB RAM, nvidia 640 with 2 GB and a 2 TB HP/Hitachi HDD.