If I remember correctly, you used to be able to connect?
What changed?
- You have a PC connected to a cable modem.
- No firewall software (this is not good).
- WinXP firewall turned off (I don't like that firewall anyway).
- Accepted some update? What was it? Microsoft broadband thingy, need more details. Who is your ISP / cable provider? It isn't M$ and I have a feeling that what ever that software is, it killed your connection.
Microsoft offered no updates related to anything ICS, IP stack or any other core functionality this week or even last week. The updates were a PKI Cert fix, the Workstation Service, an I.E. security update du-jour, Win API control box update, ActiveX update (activex bad, m'kay), another local BO problem, yet another BO in Messenger Service (which you should have turned off anyway) and other patches this month were for Medai Player and I.E. (again).
On the topic of firewalls, consider using this.
ZoneAlarm Basic. It's free and works VERY well.
If you install it, be sure to run MW4 in a window, not full screen, this way you will see the pop up from ZA asking if you want to allow MW4 network access, click yes and the check box to remember your choice for future play. If you are full screen, you will never see the popup and it will look like your system locked up.