Internet Security and resources

i've been noticing lately my hard drive LED going a little crazy and did some looking into it and   Norton Internet Security is the culprit. so far today, it's done over 5 million reads and writes. my questions are:

1) why is it doing that?

2) is there any way to slow it down and/or stop it altogether w/o just shutting it down?

 

i need to know before my hard drive crashes and before i renew my subscription?