what motherboards (socket type) will take an Athlon 64 x2 4400?
Here is a link to help you find your answer, http://www.cpu-world.com/CPUs/K8/TYPE-Athlon%2064%20X2.html
You will see that there are a number of processors that have that number, some use the 939 socket and some use the AM2 socket.
You will need to use the code on the lid of the processor to get the specific info for it.
You can also use Wikipedia to find more info on processors, sockets and motherboards.
MODERATOR NOTE: I am glad to see you have resolved your issue. To help keep this post on topic and help other with a similar issue, I am locking this thread.
Retrieving data ...