My Internet suddenly got really slow?

I think I got a virus on my computer because everything I do online now is ridiculously slow (as if my computer is like 10 years old but i just got it in September). I even tried connecting to other people's Wi-Fi (they have really good Internet connections) and it was the same.

The really weird part though is that everything that does not require the Internet runs exactly like it did before. It's only the Internet that got really slow. It was pretty sudden too.

For example, I just tried playing sims 3 and I was using a really huge house, but the game was running great! It's as if I'm using two different computers when I switch between offline and online tasks.

The computer is a Lenovo and runs windows 7. This is so annoying, please help!

Lenovo U41 keyboard problem?

Whenever I press G in my lenovoU41, the shutdown confirmation window arises and pressing the Up arrow, it closes any window that is opened. It happened all of the sudden.