HKLM\SYSTEM\CurrentControlSet\Services\i8042prt\
The Parameters subkey stores data for the i8042prt driver. The i8042prt driver controls the keyboard and PS/2-compatible mouse for the Intel 8042 controller.
For Windows 2000, many of the entries in the Parameters subkey are used only when a device is installed. When the system recognizes a new device, it copies these entries from Parameters to a device-specific subkey in the Enum subkey. Thereafter, it uses only the entries in Enum. For more information, see the entries in the Parameters subkey.
Caution
Do not edit the Enum subkey. To change the value of entries in Enum, use Device Manager.