LLTD Timer

Bought new Acer Portable model 5610. Problem is when hooking up to a secure net line I am able to download one page i.e. MSN.com and when trying to continue to another it states network is not available. However if I go on to a nonsecure network, I can stay on. Have taken to the Geek Squad at a couple of the sales places. They hadn't a clue as to the problem/solution. I do know that the LLTD Timer shows the lease on the network expires after one second. How do you change the timeing in Vista. I have searched high and low thru all the switches and can't seem to find the one which sets the timing.