IP Address Conflict and Packet Loss

[TrouserDemon]

So recently my whole house has been experiencing heavy packet loss, around 50%, sometimes worse. After changing everything, one by one, and various calls to the ISP, we finally narrowed it down to one of my housemate's laptop. When it is off, we get no packet loss. When it's on, the packet loss is there. Now, his laptop is also having messages about an IP address conflict on the network. I'm assuming those issues are related, though they might not be.

The strange thing is though, I can't find any source of the conflict. He's on an address that no-one and nothing else on the network uses. I've tried having him use a new address, and I've tried changing around everyone else's address, but both problems persist. Something is wrong with that laptop, but I've run out of ideas as to what it might be, and how to fix it.

[djjkxbox360]

Have you tried resetting the router?

[TrouserDemon]

[QUOTE=djjkxbox360;38624216]Have you tried resetting the router?[/QUOTE]

First thing we tried. We've also had all devices on ethernet and wireless. Same problem regardless.

[djjkxbox360]

Hmm yeah sounds like a problem with Windows on that laptop. To see if it is some glitch between the router and the laptop you could try running a Ubuntu live cd on the laptop causing the problem, and see if the problem still arises when the laptop is connected to the network on Ubuntu. If it doesn't, then something is screwed up in Windows on that laptop

[Nafrayu]

Is the laptop configured to automatically retrieve an IP address from the router? Because it doesn't look like it is

[TrouserDemon]

[QUOTE=DrogenViech;38624573]Is the laptop configured to automatically retrieve an IP address from the router? Because it doesn't look like it is[/QUOTE]

We tried it with the standard DHCP assigned addresses, to no avail. I also tried manually setting everyone's IP so something apart, just to make absolutely sure that there's no overlap. Everyone is definitely on a different address. With both the auto-assigned ones and the ones I set manually. In both cases windows alerts about an IP address conflict.