"Access denied" for every connection attempt after some time

[Guest remove spaces]

Hello,

I installed Vista about a month ago, and since the beginning I have this

strange issue: after some hours (between 10 and 30 approx.) my computer

is not able to create any TCP connection for from 30 to 180 minutes.

I don't know the cause of this problem but here are the symptoms:

- if I try to open any TCP connection, for instance my browser to

http://www.google.fr, I get "access denied error"

- active connections still work, e.g. IRC or Webradios are still up and

running

- my computer is accessible, for example if from another computer on the

LAN I try to access the FTP server which is on my computer, there is

absolutely no problem.

To sum up, my computer cannot establish a remote TCP connexion.

 

I am using Windows Vista Professional, which I had with the MSDN

Academic Alliance between my school and Microsoft.

 

I hope you will be able to give me some leads, or better, a solution! :)

 

thanks

 

Benoit D.