Recommend getting SpyBot Search and Destroy
its free..
Run it in safe mode
use the ADVANCED tools .... look to see if you have any
TCP/IP Stack redirects.
you can check before this by trying to go via IP address
try to ping or tracert to this ip address: 216.109.117.106
that is one of the yahoo.com servers and usually allows
ping/trace
If you can ping it via IP .. then most likely you have
something redirecting your DNS and Web traffic via
spyware, and quite possibly something that is hidden from
your normal view in the task managers' task list.
To find out for sure, you could download PSTools from
www.sysinternals.com .. they are free.. commandline only
tools that can show more information than comprable
microsoft tools. You would really be after PSLIST to list
all the running apps/services on the machine.. if you
don't know what you're looking for.. then compare some of
the running apps/services with the list at
answersthatwork.com ....
http://www.answersthatwork.com/Tasklist_pages/tasklist.htm
task list programs
good luck !!
-T