youtube problem

hello .....i got a big and strange problem with youtube ....when iam watching any video on youtube ....after about 3 min the internet stop working and i should disable and then enable the ( Local Area Connection ) and sometimes internet back to work and sometimes not ....even when iam try to download any video from youtube same problem happening with any download program and with any browser ......the most strange that any download from any anther server lke mediafire or rapidshare .....its downloading normal and facebook videos is working normal too
...........so anyone can help me please ...........