Scott bought a Dell OptiPlex and it doesn't have a sound mixer utility for SoundForge. Leo says that it should, especially since Scott sees a microphone. It may not show up from the right click menu on the task bar, though.
Scott should check his sound and task bar settings. He can also try to install the drivers from Dell. The sound card may also need to be enabled in BIOS. Also, he should check in the Device Manager (Windows Key + X) and see if the drivers are missing. The chatroom says he may need to install ASIO drivers for SoundForge.