Power Management

I have recently built an athlon 1800xp on a gigabyte dxr7+ mainboard with the latest bios i have a creative 5.1 sound card latest drivers and a radeon 64mb ddr graphics card. I cannot get the options to enter power saving modes, standby and hibernate under windows XP. As far as I know all drivers are compatable with power saving and it is enabled in the bios so I need help on this one i know that there was a file under windwos me called nohiber that listed the culprit but cannot find a similar file under xp any help welcome.