you got some kind of spyware or adware on your computer.
if you see www.msn.com and you see 401 page not found you
might have some kind of spyware or adware. tell me if you
do. because i've encountered the same problem when i got
infected with adware on my system.
First scan with Trendmicros Housecall http://housecall.trendmicro.com/
Choose "new scan" and permit Trendmicros ActiveX module to be installed
then choose to scan for both virus and spyware
Then reset your hosts file:
Download Hoster: http://members.aol.com/toadbee/hoster.zip
Unzip, install the program and run it.
Press Restore Original Hosts and press OK*
Exit the program, and you should now be able to access the sites you
need.
MSAS then protect your hosts file after this reset.