My hard drive is constantly working and this slows down my computer. It is not very big deal when I am surfing internet or listening music but during gaming it is a real pain. I have checked computer for viruses but Norton Security did not find anything. So there must be another problem. I just hope that hard drive is OK and that something else is causing this constant activity.
I see you mentioned Norton Security Suite. I think that is the source of your problems. It has a nasty habit to constantly check files and processes and that is where hard drive activity comes from. Not to mention constant processor activity that also could have impact on computer performance. During gaming you should close this software or install some other anti virus software.