Problem with ONLY 1 wifi network (Looses signal)

I have a problem with some configuration regarding my wifi card. I've got a laptop (so wifi is built-in), and i used to have no problem connecting to my University's main network. I've installed a few programs and drivers sush as bridges, tunnelers, anonymizers, etc; and in the middle something got damaged.

You'll see, i can acces EVERY network on the planet, but i can no longer acces my University's one. I get connection, it's fine for like 5 seconds, then it drops signal, it says null conectivity or limitated, and then it disconnects (and then all over again). My University has got an open wifi, but you have to log in some sort of Proxy, in order to gain acces to internet.

Sometimes it won't let me even connect to that Proxy. What can I do? Where should I look?

Thank you!

PS: Just to clarify, i'm a computer's engineering student, so i pretty much tried everything i know (the EASY things):
- Uninstalling all the crap (such as widecap, proXPN, etc). But the problem came long AFTER the installation of those programs, so i don't think it's that. Didnt' work.

- Fully Uninstalling wifi card's driver and installing back. Didn't work either.

- Going to my Linux Mint to see if it was HW related problem. It works just OK, so it is NOT HW related problem.

- Monitoring with wireshark (i know a bit), and I didn't see anything off or unusual.

Please, help me, I'm really really pissed off by this...

I simply restored windows 7 sockets, since i thought the problem might be there, and it worked! Thanks to all that visited my post, even if no one answered.

TIMINeutron