|The first link below is for an internal modem that has answering machine capability in addition to the normal functions.|
The second link is for a similar USB external modem.
I am familiar with the first vendor but not the second.
Both only state compatibility with Vista or older. They should also work OK with Windows 7 because the OSes are so similar.
Do you know if there is an internet provider available with a local number you can dial? Otherwise you may incur long distance charges.
Have you looked for a driver update for your existing device? May also be possible to run it in a WinXP compatibility mode.