whole network down during copying file across network

[phonkeo]

any one help me please!
I installed new server yesterday(Debian), every time I tried to copy files from server to other computer the whole network stop working: the client can not get ip address the a few minutes later it start work again.

I thought it was because hub or network card stop working but after I change to use new one the same problem occur.

thank in advance

[phonkeo]

I install Debian on Ace altos G330 MK2 few days a go, then every time I try to copy files from Client to this Server or From This Server to any Client, about 5 minutes after that the Server Hang then 3 minutes after it hang every come to work again. I don't know what is really the problem, I change Hub, Router, Lan Card but nothing better.

please! I need help!

thank in advance for any one who spend time few minutes for me!