Wake up from S3 by USB in XP

I did a search in the internet and came across this article first. Then I found the MS KB article titled Description of how to enable the S3 system power state for standby when USB devices are armed for wake. I had to create a new key named "usb" under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and then add a new DWORD value as shown below:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\usb
"USBBIOSx"=DWORD:00000000
I needed to reboot after I made the change to the registry. Afterwards the power management tabs appeared for both the HID keyboard and mouse. I was able to enable either the keyboard or mouse or both to wake up the system from S3 standby.