Getting back DMA mode in Windows
ATA drives that run in PIO mode instead of DMA mode use a lot of CPU any time that data is transferred to or from the drive. This can cause significant performance problems. Common symptoms are slow boot times, erratic or stuttering mouse movement, CD or DVD burning failure, and stuttering while watching DVD movies.
I’ve used this method countless times to re-enable DMA mode on stubborn hard drives and CD-ROM drives:
Getting back to DMA mode in Windows
That post says Windows XP, but the technique is the same for Windows 2000, Windows Server 2003, Windows Vista and probably Windows Server 2008.
