The WinME Promise Ultra66 (TM) IDE Controller (PD) is a hardware component designed to enhance the performance of the IDE (Integrated Drive Electronics) hard drive connections on a Windows-based computer. Specifically, it provides support for Ultra ATA/66 transfer speeds, which allow faster data transfer between the motherboard and storage devices (like hard drives or optical drives) compared to the standard ATA/33 connection.

The Promise Ultra66 IDE Controller is typically used on older computers that require a Promise Ultra66 PCI IDE controller card, which is installed into a PCI slot to support additional IDE drives or faster hard drive performance.