DNS Names Will Not Resolve

I recently upgraded a Windows 95 machine to Windows 98. After the upgrade, TCP/IP was only partially working. I could ping an IP address successfully, but DNS names would not resolve. Additionally, trying to open a web site by IP address resultedin the DNS error message. (I tripled checked the TCP/IP settings as assigned by DHCP and they were right). Renaming the Windows directory and doing a fresh install corrected the problem…at the expense of having to reload all the apps. I can’t help but think that there was a registry setting or something that I could have changed and got it working, but exhaustive searches of the internet were fruitless. Any ideas of what was wrong and how I could’ve fixed it?