Help me pick a CPU

[Teokun]

Hey guys, I just received three old computer and I'm just trying to build a pic using part from the three old one. I am not sure what kind of motherboard I have but can you guys help me choose the CPU?
http://ark.intel.com/m/compare/27513,30783,36463
These are the options.
Idk which one is the best to run.

 

[matt4x4]

You need to know what motherboards you have, what chipset they are in order to pick a cpu.

 

[Teokun]

Turn out you were right, the motherboard were made specifically for each processor because when I change processor, the PC power on but nothing work (keyboard, mouse, image). So I just put everything back where it belonged.