REnseignement

Hello,
really i know a little about laptops. i want ur help
i have a Toshiba laptop using Vista
every time i restart my pc, i have to update my windows to work better on internet or if not, every 10 seconds it disconnects itself.... or when i update the windows, it works.
and what i noticed that every time , it updates the same file : Intel - Networking - Intel(R) PRO/Wireless 3945ABG Network Connection
i dont know why it's not saved from the first time. every time i have to re-update my windows to fix the problem...

can you help me ?