Router location

[#1]

Hi all,
We've recently moved in to a new house and if I put the router close to the main BT socket, my desktop computer (in an upstairs office) doesn't pick up the broadband signal. However there is a phone line which goes up through the floor and into the office, and if I plug the router in here then it works, however this probably isn't helping our broadband speeds. All our other (mobile) devices work from the rest of the house so it's ok for now, but what would a better solution be?

Thanks in advance for any help!

[#2]

Best solution would be an Ethernet cable from the router to your desktop PC.   If there's phone wiring, can you follow the same route to run some Cat 5e (or whatever you choose)?   Second choice in my mind would be powerline adapters, although I'm not a great fan of them myself.   As an example TP-Link part "TL-WPA4220KIT" could give you both an Ethernet connection to the desktop PC and also an additional wireless access point function to increase your wireless coverage.