When you enable Hyper-Threading in the BIOS of a Windows XP-based computer, and start Windows XP:
1. The hardware abstraction layer (HAL) is upgraded to a multi-processor HAL (if required).
2. The number of processors installed is doubled.
3. Your are prompted to restart your computer so that the new settings can become effective.
For information about Hyper-Threading, visit http://www.intel.com/technology/hyperthread/index.htm?iid=sr+hyper&.
NOTE: Even though Windows XP Home Edition supports only one processor, Hyper-Threading allows the Home Edition to take advantage of the virtual processor.