[PROBLEM] Severe Internet Connection Loss

Greetings MG community,

I'm currently trying to fix a friend's PC that is unable to connect to the internet. I'm having some trouble and could use some input.

A brief synopsis of the current situation: The PC is set up in conjunction with a wireless network. Comcast broadband feeding in to the router (Wireless Linksys) for signal dissemination to two other PC's in the household. The main PC currently with the connection problems is wired directly to the router. Uses on-board NIC.

The PC had, within the past 30 days, stopped being able to access the internet. My friend is unaware as to when exactly the issue started to occur and doesn't recall making any system changes, installations or uninstallations during that time frame. When a ping is done to external servers (ex. google.com, msn.com, etc.) positive TTL replies are received. Also, access to other PC's on the network is available. The separate PC's have since been removed from the network in the chance of this being a potentially damaging virus. Here is a listing of troubleshooting techniques I've tried already, none of which have been able to resolve the issue.

Troubleshooting Thus Far

• Checked RJ45 connection terminations and wiring, also signal to NIC card. All correct and functioning properly.

• Connected secondary PC to router with same cable from the main PC. Internet working fine.

• ipconfig returns correct IP address and resolves to correct static IP issues by ISP when connected directly to modem. DNS & DHCP functioning properly. /release /renew and /flushdns were used in this process.

• Attempted Windows System Restore to the only point available dating before the issues began. Restore failed.

• Installed Advanced Windows Care (IObit) and ran full scan/cleaning procedure.

• Installed Lavasoft AdAware and ran full system scan. Cookies only threats detected aside from one, "msmssrv.dll". This file has been placed in quarantine and pending deletion. My research found that it is potential malware but I've seen mixed comments about it on the web.

• Ran full system AV scan with McAfee. Nothing detected.

• Uninstalled TCP/IP protocol from PC, rebooted, and reinstalled protocol to reload tables.

• Uninstalled network card. Rebooted and system reinstalled card properly with correct drivers.

• Checked hosts files for external name resolving.

Things To Note

• tracert command kicks back an error of "unable to find device" or something to that effect. I'm sorry that I'm unable to give exact error message at the moment but might help someone if they can link this to anything.

I've attached a HijackThis log as well just in case this might be somewhere in the malware field of issues. I apologize for this being such a mess. This is time critical for my friend and I want to be able to help him as best I can. Any input or advice you can give on the matter would be greatly appreciated, I'm fresh out of ideas. Thank you all advance.