well if the computer don't boot up then you cant get the data off it, however since you are willing to try new things do this. you see the battery on the motherboard? looks like a oversized watch battery. pop that out for like 30secs (while the power cord is not pluged in) then pop the battery back in and then plug the computer in hit the power button (if you have to) and see what happens.
Also do this: once you start the computer up or turn it on keep hitting F8 it will bring up a menu to start windows normally or start windows in safe mode and other things. You want to start it in safe mod. Then from there run any anti-virus software or highjackthis. you might beable to transfer your data while you in this however i am not to sure since i have never tried to transfer data while in the safe mode.
If that still don't work i am sure i can come up with somehting else to have you try
If you have aim contact me: ilovenichole269 and we can work it step by step theres also some bat files which you might need to load since some virus's target it and destroy it and there needed for windows bootup.
edit: your guys problems were most likly jsut bad sectors within the HD's. this is most likly damage by a virus.