Having trouble with my wireless internet

[Zhan]

My wireless internet that I share with 9 other ppl has stopped working. I don't know what the problem is, can anyone help? Is it my settings? I don't think it is...otherwise it wouldn't have worked from the start (its been working for half a year until it screwed up) Is it the internet provider?? No one in my flat can connect to it..Is there a possibility that we all caught a virus or something? Will it spread if we all use the same internet and share the same router? Could it be the router problem? Maybe the hardware like the access point or reciever problem? Its just so weird..all 9 of my flat mates were using it with no problems until it just fucked up on us..it will work again from time to time but mostly we can't connect to it. Our landlord suggests its not the internet problem but our settings, because the technician can apparently get it to work. The landlord says she can get the technician to help and if it is the internet problem then she will pay. If it is our settings problem then we will have to pay. Its a pretty large amount, so I really don't want to take the risk yet. So guys do you know what the problem might be? If i can somehow narrow the possibilities down then I can decide what me and my flatmates should do. Thanks.

EDIT: I checked my router, it is a dlink..and all status lights seem to be working..I've turned it on and off to restart it many times, but to no avail. On my computer it states that the connection is connected, and I am recieving a lot of bytes, but ain't sending enough...I can't load any webpages or anything..