I have lost my Yahoo page and when I go to internet explorer it says this page cannot be displayed, also I lost my Yahoo address bar,

Can you access any other sites on this computer ?
If not ensure it is connected on BOTH ends.
Failing that completely clear your internet cache and try again.
Tools > Internet OPtions > Delete Files, History and cookies.

Also run a spyware check as well as a virus scan. There are various malwares out there that will prevent a particlular page from being displayed.


Good Luck