Vista - Vista x64 and internet compability problem

Hello

first message on this forum
i'm a Vista x64 user since one year. I experienced some good thing, i'm using vista 64 for 3dsmax 64 and i use at least my 4 gig of ram...
But i got a udge problem, my internet has crashed yesterday for the 4th times. It means, that I have re installed 4 times vista (cause repair doesn't work)
Ok, what happens exactly: each time it becomes when I boot the PC. then when it's booted, all my internet applications crash attempting to display an url. I try to connect via firefox, trillian (chat software), filezilla (ftp soft); live messenger, IE 7 x86.
I can ping google, all my widgets works... (here is a screenshot, in french...)
The best Dialog box is on the bottom, it says: Windows has detected no trouble with the network on your computer. It appears to be a Socket connection problem.
So, actually, i'm trying to focus on the bugg, is it my PC, or windows;
My problem whit that, is it happens at any time... whitout any special action from myself

I'm actually plans to go back on XP
but vista is really better to work
any Ideas?

thanks