I upgraded from Windows 98 to 2000.  Everything worked normal except
Yahoo web mail which went into super snail mode.  I am using Internet
Explorer 5.0.  All other web sites are fast and working normal, as
well as Outlook Express.  Yahoo mail is the only problem.  I get a
message something like: (If you see this message your browser settings
are preventing automatic changing of URL)  I find no setting in the
browser that will fix the problem.  A correct answer to this question
is to tell me the fix.

Try upgrading your Internet Explorer to the latest version at
http://windowsupdate.microsoft.com

I believe this will work for you, use latest Internet Explorer.

Try Firefox at http://www.mozilla.org/firefox

Try using Google Pack at http://pack.google.com

It's fairly safe to assume that if you are running IE 5, you have not
run Windows update.  It is very dangerous to use an unpatched Windows
machine.  I'd strongly suggest you upgrade to IE 6, and immediately
hit tools->Windows Update from inside IE 6.

Also make sure you download and use a firewall such as zonealarm.

Both comments were correct.  I downloaded 6.0 and the problem fixed. 
I don't know if either of you are official Google researchers.  Thanks
Ron