Hi, trying to upgrade an old ecs 775 motherboard from celeron to a core 2 duo. Every time I start it up after the swap, I get a black screen. I put the old CPU in and it works again normally but says the CPU has changed and to check settings. What do I have to do to get it working?? I've never changed a CPU before. It was my dad's old machine before he passed and it would a lot if I had it running some early 2000 applications and games etc. any help would be very much appreciated. Thanks a bunch!