Question : Problem: Computer goes crazy

This problem has baffled me as it has been going on for awhile now.  I built a PC totally and all is well when I have it here running.  No problems whatsoever.  I've run it for a week straight from morning till night after I built it.  When I take it over to my friends home, and set it up to run, it is like a different machine.  The screen saver locks up, a usb port light goes off, and in Device Manager it has a yellow triangle in front of it along with another usb hub.  It won't recognize a usb card reader that I used  to put photo's into its Kodak program.  The system is
Win2k,  
Bio Star mobo
Amd 2.2 processor,
video & sound on board,
WD 60gb hard drive,
! gb ram,
2 cd burners
hp printer
visioneer scanner
power supply 450 watts

I have brought the PC home and all is well, I take it back to my friend and it does all this crazy stuff.  I even changed all the cables.  I don't know what else to do with it.  I am baffled.  Can anyone help?  I have taken everything out and put new components in to no avail.  It just goes crazy when it is in his house.

Answer : Problem: Computer goes crazy

magnetic disturbance from something? try in new location

power source bad? check with volt / amp meter

Same if internet cable unplugged? modem bad

Use your monitor / keyboard / mouse. any change?

Has friend got ghosts?