4-got password

@Sylvia1313 on your T-Mobile gateway, I think you will need to do a complete reset, meaning hit the reset button on the bottom or backside of your gateway, and use your T-Mobile Internet app to set it up again. Many people have said that they write their password down on a piece of paper attached to their gateway (unless someone breaks into your house, nobody else can see it). 

I hope this helps!