Heck yes. Why spend lots of money on calls when there’s a PC around the corner? You can use Yahoo! Voice services on any PC that meets our system requirements and has Yahoo! Messenger installed.
System requirements for using Yahoo! Voice with Yahoo! Messenger for Vista:
A broadband Internet connection is recommended, though not necessary.
Note: If you are using Yahoo! Voice services from a public PC, please make sure not to save passwords on that public machine. Also, make sure you log out of Yahoo! Messenger and any Yahoo! websites to keep your account secure.