I have a problem that has been plaguing me for several months now. We have a pretty decent internet connection (I did an online diagnostics test the other night which showed it as being 404k, whereas the company advertises it as being 1.5mb). On a good day, I usually have pretty low latency and can keep up with most PvPers. I would say that when things are as they should be, I pull roughly between 70-110ms to Baja with 0% packet loss. My sister, who plays Warcraft, pulls about 60ms to Silver Hand. Well, that is when things are running smoothly. When a particular computer on the network is turned on, the whole thing slows down to a craw. We've narrowed it down simply by noticing which computers on when we have the problems, and how the problems go away the moment it is shut off. The computer, which is my moms home business computer, is hooked up through a switch. When it is turned on, my latency almost immidiately shoots up to 600-1500ms with 0-50% packet loss. At one point, my sister was telling me she was seeing 3000-15000ms, and couldn't stay connected to the server for more than ten seconds. You turn this particular computer off, and immidiately we jump down to our original latency and everything is fine again. We can several computers on the network running games (UO and Warcraft), streaming video, voice chat, and we hardly notice a difference. You turn on that one computer, and even so much as pulling up Stratics is a slow and painful experience. So I checked her computer. I ran tests. I got her the latest version of AVG, Spybot, AdAware, and CCleaner. I ran everything. AdAware picked up one significant piece of malware, but we seem to have quarentined and taken care of that. I went through with Windows Defender Software Explorer, and nothing seemed out of the ordinary. I am at a complete loss as to what on her computer might be causing this. She uses Outlook, and some program called Turbo Lister for eBay. But the computer simply has to be on and connected to the internet for us to have problems. Anyways, as far as our setup, we are running Clearwire Wireless, which is suppose to get roughly 1.5mbs bandwidth (Yeah, right). We'd be on Cable or DSL if it were offered out here, but currently nothing is available. We also are on a DLink DGL-4300 108mb Gaming Router (I want to upgrade to the Gigabit version soon). All the computers on the network are running Windows XP. Any thoughts on what could be causing this?