My Boss is Spazzing Out

The Boss just upgraded his PIII-700 (Asus mobo w/ Intel chipset and EIDE (ATA100)) from Win98 to WinXP Pro and the HDD light is now on more than it’s off. Sure, it’ll go out occasionally, but by and large, it’s on. Now it doesn’t sound like the HDD is actually DOING anything, but he’s still freaking out becasue this is unexpected behavior.

What can I tell him to reassure him that this is normal and is not affecting the performance of the PC?

How do I fix it? He says he likes to know when the HDD’s busy so that he can gauge his computer’s load level and activities.

Thanks!