Either P2P or what you downloaded can hijack the windows sockets (WINSOCK). It causes things like that.
Here's a discussion where we had to peel out the P2P and more to get the machine working again. If you are asking me how to use P2P without this issue, I must bow out. My choice there.
But do read http://forums.cnet.com/5208-6142_102-0.html?forumID=5&threadID=218013&messageID=2320320
For technical reason: I use a Intersil PRISM 802.11g Wireless adapter, a Speed Touch Home Modem (Alcatel) and a NetGear MR814v2 Router.
Ever since I have had my wireless connection, I have had this problem, only recently has it been getting worse. When I use programs such as Limewire, uTorrent, or Kazaa to download large files, actually to tell you the truth any size files, even 1MB, I often get this repeated connectivity problem. I usually get away with files under 20MB because they are quite small and don't take long to download. But lets say I am downloading a movie that is 1GB. Often after 15 to 20 min, I lose the connection to my router. The little monitor icon on the task bar which represents the internet connection gets a big red X next to it. I try to reconnect to the router, but it doesn't work. So I disconnect the entire wireless network and try connecting again, but that doesn't work either, often it just freezes up. Sometimes I try repairing the connection only to land on a dead end with more freezing up. So while I still have my current session active, I can never connect to the internet. I must restart my computer and the connection usually seems fine after that until I do the same thing again. This is really frustrating because if I download files through Internet Explorer or Firefox, large ones at that, it works totally fine.
I have called my ISP provider numerous times they keep telling me that my modem is fine, there isn't a problem, I should update the drivers to my Wireless adapter and router. I have done that, i have even reformatted the PC and reset everything and still the same issue. I thought for a while the provider was the problem, I changed to a different, bit more expensive one for 6 months, yet the same problem, so now I switched back. The problem can be solved if I stop using those programs, but I find that being a stupid idea considering friends of mine can flawlessly download without this problem. Even my sister who is connected to my router, can download without the computer disconnecting. Possibly my wireless adapater has a problem, I have searched for updates, but only to realize that the company that originally made it, sold of its wifi adapter production to another company and the model has been discontinued.
As you can see I am really unnerved by this problem. I could really use some help. Anyone with similar problems or solutions would be of great help!