Hi, I recently set up a new system - antec sonata III with 500W psu - case - p5q turbo - Intel Core2 Duo E8400 - Patriot dual-channel Matched DDR2 4GB (2 x 2GB) - Nvidia gforce 9600GT Zilent 1gb - 2 HD sata everything seems to be working fine, except that when i fired up the psu for the firts time, all the fans and the HD's start running. I didn't push the powerbutton at that time. I tried to shut it down by pushing the powerbutton for 10s. That didn't do anything. I then pushed the powerbutton and the system started to boot (bios ok, xp install ok, ...). XP is now installed and working properly. But the problem remains. When the on/off switch of the psu is "on", all the fans and HD's start running. If i push the powerbutton, the system boots properly and i can work fine. But when i shut down windows (XP), all the fans and HD's keep running. Only thing i can do is switch the on/off button of the psu. I tried updating the bios (EZ flash) and clearing CMOS but no luck... Anybody has an idea of what the problem might be? solutions? thx alot Tom