Hello. i read many of the posts about similar problems but could't find something to help me. i have an old pc (Celeron 700MHz, QDI Advance 9 motherboard) and have connected on it only one ide HD. it is a WD 20Gb. The problem is that i get the classic "disk boot failure, insert system disk..." error at startup. i've entered bios and realized that it doesn't recognize HD not even when set to auto or manually. i tried to flash my bios but problem remains. after that i tried to set Delay for HDD to 15 sec but this didn't helped either. the connection are all ok i have triple checked them and i also used new cables just to be sure. i have removed jumber and also tried on cable but again no luck. the HD works ok though on other pc so it isn't HD problem. the thing that makes it all more confusing is that i tried to install windows XP pro and the installation saw the HD and even formatted it (!!!) but when i reboot to continue installation from HD i get the same message. if anyone has any idea that would help me i would be grateful !