Question : IP Stack Corruption

I have a Windows XP computer which obtains an ip from a DHCP server. It gets and ip address and can ping internal and external ip addresses.

I cannot ping a host name i.e. www.yahoo.com. I believe i have a dns issue. How do I fix this?

Answer : IP Stack Corruption

The issue was the AV. I uninstalled it and re-installed it. This solved the problem.