Suddenly one day, when i use netzero as usuall to conncect to internet, my pc didn't work as usuall, rather it restart. I tried in the following couple of days, such problem still exist. Yesterday i tried again, it conncet to internet as usuall, but today, it seems refuse to work normally again. During this period, i don't do anything about my pc.

want pc expert's help. bunch of thanks in advance.