Port closed

I think the port needs to be open so others can see you and your files rather than the other way around. Routers normally block incoming data rather than outgoing data. If you cannot browse other peoples files then they probably have their listening port blocked or they are simply on the other side of the world from you with a poor internet connection.

It is worth learning how to open (forward) ports on your router as upnp auto port mapping is not always reliable.

follow the guide for your router here
http://portforward.com/english/routers/port_forwarding/routerindex.htm

Those port forwarding guides are often a little bit overly generic. They don't tell you anything about how your software (like Soulseek) may in fact be capable of automatic port forwarding via UPnP or NAT-PMP, and that you just need to pick the right one and make sure your router is accepting requests made via one of those protocols.

This particular guide also tells you to install some random program to force your computer to use a static IP address on your LAN rather than using DHCP to have one assigned to it by the router.

Turning off DHCP and using static IP address, if you ever need to do it, is something that doesn't actually require external software, which makes me suspicious of that site! Their software could be adware or could be carrying malware or be difficult to uninstall.

Besides, using a static IP can prevent your computer from working on other networks, like other LANs (including WiFi networks), if they don't use the same addressing scheme as yours. In my opinion, if you want things to just work with a minimum of fuss, you shouldn't stop using DHCP unless your computer never travels.

Like a lot of programs that need to act as a server accepting incoming connections, the Soulseek client first tries talking to your router via UPnP and/or NAT-PMP in order to get the router to configure the port forwarding automatically. So as long as your router is configured to accept messages in one of those protocols from your LAN, Soulseek should "just work" without you having to do anything special.

In SoulseekQt, check your UPnP and NAT-PMP toggles under Options > Login. Restart the software if you change anything. It should be OK if you have both toggles enabled. I used to have NAT-PMP turned off because I knew my router only spoke UPnP. When I swapped my old router out with an Apple Airport Extreme this year, I had make Soulseek use NAT-PMP instead to get the ports to open automatically—much easier fussing around in the router configuration.

Some routers come with UPnP or NAT-PMP disabled by default, because when you allow automatic port forwarding, any device on your LAN can begin accepting connections from the outside world, which is a security risk. But so much software (especially games) need to do port forwarding, I think it's more common now that most routers just come with it enabled.

I still think UPnP and NAT-PMP is unreliable and unsecure and should be avoided. Once you get to grips with router settings and manual port mapping it only takes a min to set up. It's useful knowledge that can be reused for torrents, gaming etc.
Do you really want your router to be set up to allow software on your pc to open ports with out you knowing about it?
Fully agree that it's simplest to use your router to assign a static ip via DHCP.

I changed the port in Soulseek and set up port forwarding within the BT Home HUB 5 software accordingly:

http://i.imgur.com/SnQzgVS.jpg

But when I test the port settings within Soulseek it says that the ports are closed, why is this? How do I fix it?

I even added this port within my firewall.

Maybe you have only done the first step.
The image shows that you have created some port forwarding rules for slsk.
You now need to associate the slsk rules to your pc.
Normally in the router setting you can find a list of connected devices and then choose which 'Game or Application' it can use.
Sorry if you have already done this and I am telling you stuff you already know.

Thank you for the suggestion but this has already been covered (identifying information has been covered over in the screenshot):

http://i.imgur.com/5ceDjUi.jpg

Any more ideas?