Sky broadband issues

[CoolFunkMan]

Well, after two weeks with no net, I'm finally back. Though my internet is already messing up, it keeps cutting out for some strange reason. It's at 54Mbps (is that even right for the up to 16mb package?) and says that the signal strength is "Excellent."

 

I'm on a wireless network, with just this current PC connected to it. The modem is downstairs, almost directly below the PC, which is using a Netgear WG111v2 usb dongle.

 

Although my BT phone line went down because it disconnected for some reason, that had to be fixed before I could even get the net up! Could that be part of the problem?

 

Thanks in advance if anyone can help.