Additional Details
found it…. here it goes

In Windows Vista, the new location of the log files have been moved to the user’s AppData directory:

C:\Users\Woshka\AppData\Local\VirtualStore\Program Files (x86)\Yahoo!\Messenger\Profiles

C:\Users\<windows_usrnme>\AppData\Loca… Files\Yahoo!\Messenger\Profiles\<yahoo_u…

C:\Users\<windows_usrnme>\AppData\Loca… Files (x86)\Yahoo!\Messenger\Profiles\<yahoo_u… (for x86 version of Windows)

in some caees the profile was in C:\Program Files (x86)\yahoo

Accessing this folder is another story, however. From my experience, navigating to the directory crashes Windows Explorer. To access the directory, just copy and paste the Profiles folder path shown above into Windows Explorer’s address bar. Change <windows_usrnme> and <yahoo_username> as necessary.