Looks like this is a power management problem if I disable sleep mode problem goes away. I've updated NIC and display drivers may have to try upgrading bios and others
I upgraded to Windows 7 64 bit from Vista. If launch browser it doesn't matter if IE8, Firefox, Chrome after a period of time if I perform any activity e.g. click on a link, open a new window, enter command in command prompt the system freezes for a while before responding the cpu, memory...