I can successfully ping my ISPs DNS servers and regular web servers from my
client computer.  When I try to use IE it  returns an DNS error no matter how
the address is entered.

Might be IE's proxy settings, however this type of symptom usually indicates
some form of damage to the TCP/IP stack by the presence of an (unauthorised)
Layered Service Provider.

Google Desktop Search is fast becoming a favourite for causing this, though
other Trojans can also be responsible.

http://wiki.commerce.net/wiki/Fluffy_Bunny_Burrows_Into_WinSock

http://www.invision-graphics.com/downloadview-details-123-LSPFix.html

http://www.castlecops.com/LSPs.html

The lspfix tool may be able to fix the problem. Otherwise you need to remove
and reinstall Windows' TCP/IP components.

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