Good morning...I'm a newby and you will see why if you read on.
I am an “amateur” user of technology

but one who can implement anything that I am told that makes sense. I have a problem which I can’t solve.
I’ve just bought a Bluetooth Lenovo A310 ideacentre desktop PC. Of course the machine is wireless. I prefer to keep it upstairs (one floor) in my room that I term an office. It is about 6 metres away in a straight line. When I bought the PC I persuaded Talktalk to give me an N router. I set all up very easily and it works well except that the machine appeared slow to respond to broadband commands. It also breaks up quite frequently when steaming, shall we say, ManU versus Chelsea last night. That is, as you all know, very annoying. My only telephone entry to the house is by the lounge window.
This morning I did a check with Talktalk’s speedtest and found that when checked downstairs beside my main the router I can get speeds of in excess of 8MB yet upstairs in the office (perhaps 6 metres away in a straight line) I get less than 1.5 MB.
So I see my problem clearly in that the signal will not carry the distance and I ask anyone who can help to offer a solution. Can I buy a booster for example or am I stuck with a second rate service of my own making?
Thank you to anyone who can offer advice.