Sound

Hello and Welcome to TSF

Make sure the service is enabled and running. There are two ways to view Services on your computer. The first is to use the MS Configuration Utility by typing msconfig.exe in the Run box accessed via the Start Menu, followed by clicking the Services tab. If you want a quick visual of which items are running or stopped, this is fine, but the information is limited. The preferred way to make changes to services is to launch services.msc from the Run option on the Start Menu. The Services window shown below will open.
I believe the service you are looking for is Windows Audio

I have restarted the service but nothing has changed

Do you have a sound card?

The modem driver is only for your modem, and can't be used for audio playback.

You need to find the audio drivers that came with your sound card (or m/board if is has onboard sound) and reinstall them.