Can ping but can't access any website with IE

After recently using msconfig to go into selective startup
and unchecking a number of programs (to stop spy and ad
ware) in the startup tab now I can not get to any website
with IE. Since then we have rechecked (√) every program in
the startup tab, but no change. The computer is running
Windows ME and is on a network with 2 other computers. I
can ping the other computers and see their shared files. I
can ping this computer and see its shared files. I can
ping IP addresses on the internet. I can tracert an IP
address. I thought it was a DNS problem, but I can tracert
google.com. Oddly enough I can not ping or tracert
ping.symantec.com from this computer, but it works on the
other working computers. (Access to internet is fine on
the other computers) Typing an IP address into IE's
address window (like http://216.92.. etc..)does not work.
I have Norton and when the machine is starting up I get
the message: "Norton Antivirus is unable to start eMail
protection. Please ensure that TCP/IP is installed. This
suggests something is wrong with my TCP/IP, but if I
change the TCP/IP properties I lose the ability to see the
other computers. Also "Unable to synchronise the
environment variables in the windows registry with the
environment variables in the legacy files AUTOEXEC.BAT
and/or CONFIG.SYS" comes up after typing msconfig. What
should I do or test? I've noted uninstall and reinstalling
TCP/IP on Win ME should be left to Microsoft dealer.