cant transfer files from my laptop to my computer

i just had my motherboard replaced by the insurance compandy because my computer kept freezing.
ive been trying all day to transfer music from my laptop to my computer over lan but its not working.. i can transfer files from my computer to my laptop though........

when i try and get onto my laptops shared documents from my computer explorer crashes. or its just really slow. then i try and transfer files and its either REALLY slow or doesnt work.
i tried playing music from my laptop over the network and it kept freezing.
but when i tried playing music on my laptop from the pc over the network it was completely fine.

any help would be appreciated.

I just put a network card in.. which seemed to fix it. and the files transfered.
however when i tried to go on the internet all the pages looked scrambled.
and when i listened to the music i transfered it was really bad quality....

so that failed.

Is the connection wireless?