"I tried to install another internal HDD + another 256 RAM (both of them are used) to my computer, operating XP with an ASUS P5P800S motherboard. When I ran the system, the new device was found by the sys. but not shown on My Computer Page, so I turned the sys. off and took both items off and turned on the sys. no BEEP SOUND, NO MONITOR , NO SYS. BOOTED, while the CPU fan runs with the motherboard green light lit and both CD Drivers lights coming on. I checked all installed components for any physical defect, replaced almost all cables and ribbons. Pulled the battery out and reinstalled, reset the CMOS by jumper, checked CPU warming up by not installing the fan for a few seconds, replaced the RAM, checked the monitor, but no lucky. The earliest response would be greatly appreciated. Hoss"