I just got two Western Digital 1.5TB WD15EARS disks. This drive has a feature called intellipark, which parks the head after the disk is not used for a while. This is supposedly a power saving feature. But, as someone explains, it can also severely decrease the lifetime of your drive.

To disable, download wdidle and disable it. This needs to be done from a dos environment. Dos bootdisks should be available for download. 

USAGE:
WDIDLE3 [/S[<Timer>]] [/D] [/R] [/?]
where:
/S[<Timer>] Set timer, units in seconds. Default=8.0 (8.0 seconds).
Resolution is 0.1 seconds from 0.1 to 12.7 seconds.
Resolution is 30 seconds from 30 seconds to 300000 seconds.
Note, times between 12.8 and 30 seconds will be set to 30 seconds.
/D          Disable timer.
/R          Report current timer.
/?          This help info.

Disabling it actually causes it to go even more beserk. In a few hours, SMART logged 5000 load_cycles, and the drive was making very funny noises all the time. Instead, I set it to 300 seconds, which effectively disables it.

Someone also made a boot CD with the tool available (wgetting it works, clicking doesn’t). I don’t think the link will be there forever though. (can I attach zips to a blog post?)

The forum post I linked to also has info about TLER, which I’ll get back to.