I came across this exchange:
>> Uninstall all of the yahoo stuff that installed along with Messenger, as
>> well as messenger itself. do a custom install and deselect all extras.
>> don't have any other programs running when u run the install. I had the
>> very same problem about 3 months ago. Messenger works flawlessly for me
>> since I installed it "bare". All of its features work fine--voice,
>> webcam, file transfer, photo sharing and conferences. What happened is
>> your install went "kaflooey" (a highly techinical term. 
)
>thank you Dave I just uninstalled the program and de-selected the extras
>and
>everything came up just fine. Thanks for your help.
Let us know if it works for you.
-Paul Randall
"queenie" <queenie@discussions.microsoft.com> wrote in message
news:7754FA6F-BF86-4F42-BC9C-3F0C73E06E18@microsoft.com...
>i just purchased this pc with windows vista,,,installed my usual
> programs,,one being my yahoo instant messenger,,but my messenger will not
> allow me to log on,,it works fine on other pc which is windows xp,,,but
> not
> this with windows vista,,please help,,use yahoo frequently