Hardware interrupt - IDE ATA and ATAPI disks use PIO mode after multiple time-out or CRC errors occur * In Windows XP and Windows Server 2003, this time-out value is always 10 seconds.
by decembre* An alternate, less-aggressive policy is implemented to reduce the transfer mode (from faster to slower DMA modes, and then eventually to PIO mode) on time-out and CRC errors. The existing behavior is that the IDE/ATAPI Port driver (Atapi.sys) reduces the transfer mode after any 6 cumulative time-out or CRC errors. When the new policy is implemented by this fix, Atapi.sys reduces the transfer mode only after 6 consecutive time-out or CRC errors. This new policy is implemented only if the registry value that is described later in this article is present. To implement the alternate behavior (reducing the transfer mode after six consecutive time-out or CRC errors instead of after six cumulative time-out or CRC errors), you must modify the registry as described below after you apply the hotfix..
