Average Disk Queue Length

I ran the Vista Reliability and Perfromance Monitor. Everything looked fine except one item. I had one message indicating the "average disk queue length is 5. The disk may be at its maximum transfer capacity due to throughput and disk seeks".

I have run many times at some interval and found ""average disk queue length " changed like 2 ,5, 8.

What should I do about this?

Regards

Rajesh

XPS M1530 Product Blue, A09 Bios, Vista Home Premium 32 bit

Intel T9300 2.5 ghz 6 mb l2 cache, 4 gig ram,
Hitachi 120 gig 7200 Sata