I have to support 11 Gateway Pentium D computers in my video lab, running XP Pro with 2 GB of RAM.  Suddenly, 2 of the machines will not boot.  Really  won't boot, as in the DVD drive light briefly flashes at startup, but the hard drive never spins up.  I don't even get the boot menu/bios screen.  I've tried the basics, nothing seems to work.  I'm not a newbie, but this mystifies me.  I wondered if was the CMOS battery; I pulled the battery and  reset it, which allowed the computer to restart in safe mode, but at reboot it went back to a blank screen.  Hardware isn't my specialty, but the fact I can't even access the bios says I need some advice.  Help?  

Drew Blanchard
Technology Teacher
Winooski City Schools
Normand St.
Winooski, VT 05404
(802) 655 - 3530 x6073