Hi - I have a 2.3GHz XPS laptop and its usually very fast. Recently it has frozen for a minute or longer, with 100% CPU usage which registers as "system idle process" and will not respond. I understand that System Idle Process is supposed to work in the background when CPU is not needed, but clearly it is interfering. One high usage among the processes, at these times, is LUCallback Proxy. I think this is part of Symantec Norton antivirus etc (I have Norton 360). How can I diagnose and fix the freeze-ups? Would appreciate help!

The process "LUCallback Proxy" is used for updating symantec products, there are normally multiple of these processes running all at the same time as each module of Norton 360 (i.e antivirus, firewall... ) are all checked for updates seperatly. This process is renound for bringing the most top spec comps to a stand still. In this case the process may simply be malfunctioning, try completely removing the product and doing another install.

Version 10 never did this. I concur with c_starrs above, except that I would stop where he says completely removing the product and not going any further. EVERYBODY is suffering from this latest "gift" from Symantec who can't ever seem to get it right no matter how many times they throw out an update. I have the absolute latest version available, was posted >yesterday< and after 3 hours of install, reinstall and deploy clients, I am right back where I started, it is no better at all. Try another company altogether, I think Symantec has worn out their welcome.