Can I improve Broadband Speed?

Good Evening,
I have a problem with my wife's Dell All-in-One PC.
It has just been upgraded to Windows 10 but she's complaining that the Internet is slow.
I am on Sky broadband, and my PC is connected by wire to the router and has a speed test result of 8.5
The Dell uses a USB Dongle and is about 15 feet away with 2 walls in between, recorded speed is 2.13.
Is there a usb wireless option that will improve this? I really don't want to run a cable from the router if at all possible?
Any help would be appreciated.
Dabber
I have a problem with my wife's Dell All-in-One PC.
It has just been upgraded to Windows 10 but she's complaining that the Internet is slow.
I am on Sky broadband, and my PC is connected by wire to the router and has a speed test result of 8.5
The Dell uses a USB Dongle and is about 15 feet away with 2 walls in between, recorded speed is 2.13.
Is there a usb wireless option that will improve this? I really don't want to run a cable from the router if at all possible?
Any help would be appreciated.
Dabber

Home Plug Adapters may be the answer - 2 plugs - one is connected by a plug into a socket and then into your router (it will not slow down your reception). The other plug into a socket near your wife's computer and then connected to her laptop. I have not tried this with another computer but I use it to allow my television to receive the internet - iPlayer etc. and it is certainly fast enough to stream programmes.

I recently purchased a Wi-fi extender as I wanted to extend my signal into the back garden.
Despite the signal having to travel through several walls and the router being a good distance from where I wanted to extend the signal to. It works very well indeed.
It wasn't an expensive one. It was about £20-£25 if I remember correctly and bought from Argos. The make was Netgear I think.
Despite the signal having to travel through several walls and the router being a good distance from where I wanted to extend the signal to. It works very well indeed.
It wasn't an expensive one. It was about £20-£25 if I remember correctly and bought from Argos. The make was Netgear I think.