What's wrong with my computer?

Sounds to me like a driver issue, or adapter mis-configuration. Without actually seeing your PC i couldnt actually diagnose, but my money would be to look in those areas

Sounds a little bit spooky...

Did you try to reinstall your network driver?

Do you have any software that might try to interact with your router? JDownloader or any uPnP stuff like tunngle?

How does your network looks like? Your desktop is connected via WLAN? Are there further computers in the WLAN?

Do all systems on the network have this issue?

I know the issue, and its rather annoying, to be honest its your connection. This is how i had to resolve mine, every day...

Open the command prompt..And type...

ipconfig /release
ipconfig /flush
ipconfig /renew

exactly as above

To be honest, it really annoyed me. When i changed to fibre, it got fixed. So maybe you have a landline or computer overloading your line.

Several possible reasons, no guarantee:

1. Your firewall blocks packets your adapter uses to obtain new IP's or maintain connection.
2. Windows BITS transfer chokes your connection for updates to a point your connection drops.
3. Your ISP is cutting your connection on purpose, some of them do this, take people's money and pretend like nothing happened (this happened to me so I sued those bastards, gave them threats and they had to pay me huge amounts of cash and secure me a 99% stable connection)
4. Your ISP doesn't have enough free IP addresses in it's IP pool for all users, can happen specially at peak times.
5. Adware infection can cause this, antivirus suites can't detect adware, use AdAware or even better Spybot Search and Destroy.

Sounds to me as if your connection cant handle your internet usage. Too much data for the cables to handle, not enough bandwidth and connection speed too slow. Hence why when you get on your computer, the whole net goes down. Best solution here is to get better internet. If you get Teamviewer (free download) I can take a look at your computer, check your router configurations.

Edit: Also just wondering, do you connect to the router via ethernet or a modem in the back of your computer?

BITS - Background Intelligence Transfer Service, aka , a way for programs to download data without you noticing or controling this. Windows update uses this, as do many antiviruses, MSE will always turn this service on regardless what you do to it.

If you have updates turned on and automatic, this will no doubt choke your connection and eventually cut it off. You can try manual updates and see if that helps.

IP Pools - A number of IP address numbers an ISP rented to use with its customers. There are two types of internet for public, a dynamic and static packet. Dynamic will automaticlaly obtain new IP each 30, 60, 90 etc minutes, while static gives you just one IP for everything and all the time. Dynamic is recommended for gamers, static for server hosts. If ISP runs out of free IP's to use, your adapter won't be able to use an IP address to connect you to the internet, and so it will search on and on. In some cases, adapters can obtain IP address (default IP assigned to some adapters) and then search for a non-default one in the IP pool.

Well, I don't know what to say. Perhaps your computer still has a new year hangover? LOL

Joking aside, perhaps if you provide more detail I can think of something.

Not sure if this is useful, but have you tried to shut down the other computers to gain the full 100 % connection speed for your PC?

When my desktop is on, the internet eventually stops working for every computer on the network. Existing connections such as teamspeak and XFire work fine, but no new connections (or browsing) is possible.

Weird. Sounds like kinda router-firewall becomes active. Can you give more examples of programs that keep on or stop working?

The router and modem are fine even when this problem is happening.

Router and Modem? How do you connect to the inet?

Another idea: can you connect your desktop via cable to the router instead of WLAN? Just for testing purpose.

For the record, a lot of fibre connections (including mine) have a router and a modem. In the order of .. line>>modem>>router>> devices.

IP Pools - A number of IP address numbers an ISP rented to use with its customers. There are two types of internet for public, a dynamic and static packet. Dynamic will automaticlaly obtain new IP each 30, 60, 90 etc minutes, while static gives you just one IP for everything and all the time. Dynamic is recommended for gamers, static for server hosts. If ISP runs out of free IP's to use, your adapter won't be able to use an IP address to connect you to the internet, and so it will search on and on. In some cases, adapters can obtain IP address (default IP assigned to some adapters) and then search for a non-default one in the IP pool.

Almost correct, an ISP will give the home user a static IP. Within the home network, it will use one of the private ranges (192.168.x.x, 172.16.0.0-172.31.255.255, 10.x.x.x) then it will connect to the internet using NAT. Turning that one internet IP from the ISP into many. That is how it is done usually nowadays. Dynamic and Static occur within the home net, not on the ISP end usually. A client computer on the home network with router enabled DHCP and on the client, will request a private address (From the private range the net is on). Once the computer goes offline, the IP is given back to the router to reissue. Static ont he other hand is a manually assigned IP to a client/router. Best used for servers, printers, etc etc.

Fluffy, thats a good point, well raised. Maybe there is a NAT/DHCP issue with the router requests/PC/ ISP.
I'm not really an expert on networking, just offering educated guesses.

Fluff the expert with them internets

Yogi, I have a 100mb/s connection and I receive over 1000 attacks a hour (regardless that this is business connection) the way I fend those off is custom fwall filters and some tools. Perhaps your firewall indeed panics. Which one are you using?

I'm using a modified version of Comodo with some custom filters that block inbound traffic harshly so no attack can even ping and check my security even. Haven't had a virus in years by now since I use this kind of protection.

Another suggestion, try your connection/router/modem with another system and see if same problem happens.

When I teamviewerd into Yogi's computer I checked the DHCP/NAT settings and what not; everything looked fine there. One thing did pop up as peculiar to me though, his firewall on the router was shutting his comp's connection down do to DoS Attacks. I'm thinking that for whatever reason his computer floods the network with data and the router shuts him down for a suspected DoS Attack. However this is only on theory I have and I could better figure it out in front of the computer itself. I suggested he switch out his wireless card with a different one, see if this is the issue, as I tested the IP stack and it was all functioning normally. I also said to try plugging in via ethernet and see if he has the same problem. Another thing I noticed is I could not follow a traceroute back to the router, but I was getting a ping through, so I suspect some interference either on the card or somewhere in between. Again, it would be better if I were on site.

@MAVEN
Having a job and degree in networking helps lol. As a network administrator for my company it is my job to work with routers, switches, servers, network issues etc etc. I also serve as the tech guy Try configuring routers and switches from the IOS command line.

Fluffy, i know exactly...I'm not sure my fix will work on WIN7 though.
A few years ago i had a fix for win XP. The issue was that it limited a users TCP connections to 10.... Does this sound like the issue here?

Hmm hmm, its possible. However, it wouldnt explain the apparent excess of data and the firewall with the DoS alert. Never hurts to try, although it wouldnt apply to games as they use UDP to transfer game data. This would account for no internet connections though as they do rely on TCP.

Use with caution ( create a restore point, please)

http://smallvoid.com/article/winnt-tcpip-max-limit.html

Some VBS (.vbs) scripts from my own tweaking tools (old projects) Designed for XP and Vista, no support so use at own risk. Run them only ONCE.

Registry backup:

' strCommand = "regedit /e "
strCommand = "regedit /e Regbackup.reg "
set objWshShell = WScript.CreateObject("WScript.Shell")
intRC = objWshShell.Run(strCommand, 0, TRUE)
if intRC <> 0 then
MsgBox "Failed to create registry backup. " & intRC, vbInformation, "Registry Backup"
else
MsgBox "Registry backup created.", vbInformation, "Backup"
end if

Create a restore point (No notification):

CONST DEVICE_DRIVER_INSTALL = 10
CONST BEGIN_SYSTEM_CHANGE = 100

strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" & strComputer & "\root\default")

Set objItem = objWMIService.Get("SystemRestore")
errResults = objItem.CreateRestorePoint _
("SASEVR Restore", DEVICE_DRIVER_INSTALL, BEGIN_SYSTEM_CHANGE)

I have one that sets custom amount of max connections, can't find it though.