PC causes internet connection issues - Interference?

[Broady]

Hi All... Im a little stumped with this one - hopefully someone can give me some direction!!

I have a small wireless Network set up, to which I have up to 7 devices connected. (PC, 4 Laptops, Iphone and a Wii).. Generally there is only 2 -3 devices connected at a time.

I do not have any issues with my laptops or other wireless devices, but for some reason, whenever I turn on my PC, it seems to slow down and eventually crash the internet connection for everyone! I have run a ping test from my laptop, and can see a significant degradation and packet loss (ie 70% to 100%) as soon as the home pc starts starts windows and then within seconds of turning off the pc, the connection returns to normal.

Currently the PC connects to the network over WIFI but I also experienced this problem with a cabled network connection to the router. I have even tried booting the computer with both cards (WIFI and NIC) disabled and this caused the same problem. So far i have done the following troubleshooting:
* Formatted HDD and reinstalled everything
* Moved the PC away from the modem / router - they now at opposite ends of a smallish townhouse on different levels.
*Replaced the wireless Network card

Im really not sure what to try next. The PC has recently undergone a hardware upgrade and has had a new motherboard and Power supply. Is it possible that there could be some sort of electrical interference which is killing the adsl2 signal on the phone line? Has anyone else seen or heard of anything like this before? The funny thing is, that during these periods of slowness, I can always browse quickly back to the admin console of the router. So it looks like the internal network connection is OK. Rebooting the router several times will eventually restore a decent network and internet connection to all machines, but this is unreliable and unpredictable (ie. sometimes 2 router reboots will do it, other times 5!)

Here is a little more info:

OS= XP Pro SP 2
ram= 2Gig
gfx= ATI Radeo 3800 Series
rounter=DLink Dsl G604t
NIC= TPLink Wireless 11/b/g (have also tried Dlink wireless NIC)

If anyone has any ideas or some further troubleshooting tips I would really appreciate them! Thanks in advance.

 

[Alvin.C]

...can see a significant degradation and packet loss (ie 70% to 100%) as soon as the home pc starts starts windows and then within seconds of turning off the pc, the connection returns to normal.

Hello,

Does the degradation occur when the home computer is turned on, but not booted into Windows (i.e. the period before Windows loads)?

Test the Internet connection on another computer while in the BIOS settings screen of your home computer - to prevent it from booting into Windows. Alternatively, you can unplug the hard drive or change the boot order settings in the BIOS to prevent the computer from booting up. On some motherboards, pressing the 'pause' key during the POST sequence works as well.