Restore DMA instead of PIO for Harddisk in Windows XP

use regedit to browse HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}
Subkeys like 0001,0002 is different channels, delete all MasterIdDataChecksum and SlaveIdDataChecksum in the sub-keys and reboot the computer. The DMA mode should be recovered

Ref:
預防WinXP下IDE介面被由DMA傳輸模式被改為PIO模式
AISCL: How to force DMA mode in Windows XP.