Trouble with Internet

My internet has been acting up lately. It started about a week to two weeks ago. My current provider is ATT U-Verse. It was never like this before for the many years I've had the service. Google Chrome and other browsers I use can't connect to the internet sometimes. My internet cuts off and reconnects at various times and the cut off lasts for a few minutes. I'm always lagging. It's worse when I'm playing Modern Warfare 2 on Xbox Live. I always cut off and get booted from games. This all happened after my brother downloaded a file from a porn website. It was a plugin for Firefox to play flash movies from the site. I believe the file was WMVPlugin. I'm on a wireless connection on my desktop. Installed a LinkSys Wireless-G PCI Adapter. It always says "excellent connection" but my computer and Xbox Live show me otherwise with all these disconnects and reconnects. All this lag is frustrating me. Belahzur (sp?) has been trying to help me fix this but thinks I should go here since he can't find anything wrong with my computer. There's no malware or viruses that we could find.

I'm guessing it has something to do with multiple packets being sent out or something. I dont know what is going on. I just want to fix this and get it over with. I've even considered reformatting my computer as a last resort if I can't fix this. Can anyone please help me? I want to correct this problem. Thank you!

do you have lag problems with the xbox when the computer is off? do you have both a dsl modem and a router or is it the modem router combo? if you have both a dsl modem and a router try bypassing the router connect the xbox directly to the DSL modem. if you still have problems call AT&T its something on there end.

i have problems with xbox even when the computer is off. I believe I have the router modem combo. I dont use any seperate routers or modems. Just the one AT&T gave me when I first subscribed to U-Verse.

bump