3 dongle wont let me access internet even with full signal strength

I have a 3 internet dongle which i have had for almost 2 years now. In the last 2 months it has been connecting and showing full strength and then wont let me access any websites due to 'connection error'. I have wiped my laptop and tried it, un installed the software and re installed it, tried a different dongle, tried a different laptop (3 in fact), and even been in to the 3 shop and got a new sim card in case it was that. Does anyone one else have this problem and know the solution as it is quite frankly driving me mad! And my 24 months contract doesnt end until November :(

Trish, you need to be a bit more specific about what worked and what did not. Are you saying that your dongle works on other laptops and another dongle does not work on your laptop?

Hi. Thanks for your reply. I borrowed 2 other laptops and tried my dongle on them both in the same house I use my laptop, and it didnt work on either of them. When it does occasionally work it isnt for very long. I have also tried another dongle with my laptop and it doesnt work. But it says full signal strength.

does that laptop and dongle combination work anywhere else? what happens if you go a few miles up the road and try?
Does it work out of doors?