At the moment, I have a wireless internet connection... but the signal strength only stays at "excellent" if I'm in the same room... If I try to get onto the internet in the upstairs part of the house (1 floor up from wifi box) the internet connection is either non-existent or low... which sucks...

is there any way I can improve the signal strength? maybe some sort of booster to buy and plug in PC? if so, which are the best ones?
PS - completely different side question.... I'm buying a new laptop soon, but do not have a clue about processors...
what is the difference between a
i7-720QM processor (what does i7-720QM mean?!)
or a dual core processor?
would any of those numbers above be able to handle gaming?

I know its generally the bigger the number the better it is... but it'd be nice to know how fast it'll be and what it can handle... any words of wisdom are welcome