CPU and Disk time

Does anyone have problems with the hard disks running at a high rate of speed ALL the time. I have cut out any indexing, programs that tend to search and/or allocate items and any other I see. However, my disk light runs at a feverish pitch. It interferes with my access time when running programs. I have cleaned registry, scanned system for cookies and other time consuming items.

I have a Vista home premium and a dual core amd processor. I also have a usb memory insert to help with searches, and, in general share in the use of the hard drive. I run a HP Pavilian

Help.....