Can't access some webs ites

Case Study - Can't access some web sites

Situation: There are 4 workstations and one windows 2003 server in a small LAN. All computers can access the Internet except one XP Pro with SP2. That computer can access some web sites like www.chigaotech.net and www.howtoentworking.com but not Google.com and Yahoo.com.

Troubleshooting:

1. The workstation is running Symantec antivirus and MS Antispyware. We ran MacAfee Antivirus and Adware, but couldn't find any virus or spyware.

2. Checked the HOSTS that has 127.0.0.1 point to localhost only.

3. Ping and tracert google.com received correct IP.

4. nslookup checked the DNS and it works fine.

5. Modified the MTU on the computer based on ping test. That didn't fix the problem.

5. Used System Restore to restore the system to the date before he had this problem. It works.