Turn off Harddisks

[Zhnujm]

Anybody knows a tool that let me turn off a harddisk after some time ?
I know it can be done with windows but that setting is always for all harddisks, i only want to use it with one drive.

thanks

[communist]

In WinXP you can let windows turn off devices to save power. Not sure if this can be done with all devices but you may want to look at device manager -> device X -> power management tab.