Replying to Computer connectivity conundrum

Assist me in my troubles ns, please. I know some of you are a lot smarter than you let on

2 years i bought a tosiba laptop. For one reason or another, it could never connect to the wireless network at home, apart from a few minutes here and there. Despite doing all the things that connectivity troubleshooting told me to do, nothing worked. Now, at school my internet worked perfectly, as it did in other places also. Literally just my house was the only problem.

So a little over a month ago, we bought a new wireless router, and it worked flawlessly, up until about 3 days ago, when it went back to exactly how it used to be, and not work ever.

I've tried pretty much everything i can think of, and nothing works. And if its important, there are 2 other laptops in the house that work perfectly, but mine is the only one running vista.

so what can i do....?

(i'm posting this from another computer, for all the smartasses out there who'd point out i'm online right now)