System using Intel D875PBZ motherboard, Antec True Power 420w PS, Nexus Multi-Fan Controller (for System Fans), CPU Fan connected to MB CPU Fan connector, Bios configured for S3 Standby mode, and BIOS (P27) - Windows XP Pro w/SP2 - All Drivers are updated. I found on Intels site that this is a problem with a USB mouse and keyboard connected to USB ports and I have already switched them to PS2 and still system will only go into S1 Standby. When in Standby the system and cpu fans continue to run, however, it appears that all hard drives do go into standby. Intel support did help me get the S3 setting to configure in BIOS, but it still does not work and only works as S1 state. Appreciate your help.