Before we get too far about using a second router, i think you need to be a bit clearer about where everything is connected, and using which cables..
- What cable do you use inside your house from the downstairs hall socket (if this is the socket that the phone line comes into from outside, it is most likely the master socket, and this is what i will call it from now on) to the socket in the upstairs room? Is it a CAT5/ethernet cable, or is it just a phone cable?
- Do you have DSL splitters in use in the downstairs hall and upstairs room?
Internal networking uses different cables to phones, so if you have a phone cable extension between the downstairs hall and the upstairs room you cannot simply plug in a second router downstairs (routers need an ethernet connection between them. CAT5 cable is the most common, but i will refer to it as "ethernet" from now, as i dont know which standard cable you are/would prefer to use).
Also, having the router so much further from the master socket could mean you are not getting the best Internet speed from your phone line.
The best set up would be to:
- Put the router you already have from your ISP downstairs by the master socket (this normally connects using phone cable from master socket to router, sometimes through a DSL splitter. sometimes the master socket has a seperate connection fro phone and Internet on it)
- Run an ethernet cable from the downstairs hall to the upstairs room
- Plug a second router in at the upstairs room at the other end of the ethernet cable, and then connect the PC in the upstairs room to the second router using the same ethernet cable you already use.
- Both routers should have wifi
This will give you a basic network, where you have the potential to add more PC's/smart devices via ethernet cable to the network either upstairs or downstairs, and also have wifi both upstairs and downstairs too.
(example, I have a router by the master socket, and then run the ethernet cable to a media center where i can plug my PS3, skybox and CCTV into a second router. In the future i will then run another cable from here to my study so i have a wired connection there too. This means I have as many devices connected via cable which is usually more stable than wifi, and leave the wifi for things which need to be able to move around - phones/tablets/laptops etc)
The next question would then be how you connect to wifi, would you want to connect to different wifi networks when you are upstairs or downstairs, or do you want it to look like the same wifi network, no matter where you are in the house?
I didn't see in your original post if you owned a second router, or if you were planning to buy another one?
If you are going to purchase one, you do not need to ask Talk Talk for one, or even purchase the same branded one either (D-Link?). Sometimes it is easier though to buy the same brand, as it means the set up menus are similar and easier to get things configured, instead of "re-learning" things because different manufacturers decided to use different ways to set things up.
Regardless of whether you buy a new router or use an existing one for the second router, you will need to perform a number of steps before you can use it to extend your wifi (best to follow mattylad's advice and google it). Those steps can include:
-disabling the second router from trying to connect to the Internet/put it into "bridge" mode (the first router by the master socket will connect to the internet, the second router just needs to connect to the first router to get the internet connection)
- disabling DHCP in one of the two routers (best to disable it in the extending one. this means only one router is allocating IP addresses to devices attached. otherwise you can get a clash and it will seem like you cannot get internet access)
- Set the SSID/Broadcast name for the wireless to the same on both routers (this allows the seamless connection to wifi between two routers/access points)
- Set the same wifi password/authentication method on both routers (same as above)
- Manually setting the IP address for the second router/making sure it is on the same subnet as the first router (less likely if the two routers are the same manufacturer).
Sorry if this post seems long and more work than you originally hoped!
Alternatively (as you did ask for alternatives!), another option is to connect an access point to the router you currently have upstairs that has a longer range.
I own the following access point, and used this in my parents house to extend the wifi signal over a greater distance to the ISP supplied router.
only thing with something like this, is that it only takes one ethernet connection. so you cannot use something like this to connect up other devices via ethernet cable, and extend wifi at the same time.
Hope you find this useful!