Power State Mappings for Disk Drives

[Fred J]

Power State Mappings for Disk Drives.
My system will not go into the sleep state that spins down my disk
drives. I found that my 'Power State Mappings' for all my volumes are
Unspecified; e.g., S0->Unspecified...S5->
However, under 'Power Capabilities', PDCAP_D0_SUPPORTED and
PDCAP_D3_SUPPORTED is listed.The 'Current Power State' is D3.

I noticed on my other system that does spin down the disks, that they
have the same 'Power Capabilities' but they have these 'Power State
Mappings';
S0->D0
S1->D2
S2->unspecified
S3->unspecified
S4->D3
S5->D3
And the 'Current Power State' is D3

Are the Power State Mappings used to put the disk drive to sleep or are
these conditions that wake the drives up? With regard to putting the
drives to sleep, is there some entry in the registry I need? Can I
specifiy the Power State Mappings?

Thank you,
Fred Jacobowitz