The only time it hangs is when I’m downloading… The pc normally runs sweet as a nut, no probs. I’ve tried un-installing BitComet and running an alternative torrent download software, same problem, once download starts it will eventually lock-up. I’ve also unplugged all peripherals ie printer/scanner etc.
Well, this leads me to believe that I was right to suspect your PC as being the source of the problem. This might or might not be a tough nut to crack.
As I said, there might be a lot of possible reasons why this is happening, so, I would proceed by elimination, in order to narrow down the area a little more with every step and to find out where the problem resides (hardware or software).
First, it would be a good idea to verify if the problem doesn’t relate to your wireless card (hardware/software). In order to do that you should try and connect (if it is possible) your computer to the router through a patch-cord cable (I’m assuming your computer has a LAN connector - the 8P8C connector also known as “RJ45” - as every computer nowadays does). If this solves your problem, then, depending if your computer has an integrated or plug-in wireless network card you can try to update the drivers or even replace the card, to see if that makes your problem go away.
If this doesn’t solve your problem, then, as I’ve recommended you in my first post you should run some specific memory, CPU and HDD tests to check every one of them for problems. For memory you could use memtest86+. For CPU and HDD there are several free or shareware utilities… just search for any one that fits your taste.
A good idea would be, to have your OS up-to-date (if it’s not already); I’m having in mind, especially, the TCP/IP stack and all the other network-related components of the OS, which get updated too, along with some of the Windows updates.
These are just my thoughts right now; they might isolate your problem or not, but you’ll need to start somewhere anyhow. 
Anyway, let us know how this turns out.