It appears you were facing issues with audio recording on Windows 7 Home Premium due to the missing Wave Out Mix option, which is hidden by default. The steps you outlined from the Vista forum can help you enable the Wave Out Mix feature in Windows 7 to resolve your audio recording problem.
To summarize the steps to enable Wave Out Mix in Windows 7:
1. Open the Control Panel.
2. Select the "Sound" option.
3. Go to the "Recording" tab.
4. Right-click on the background of the tab and select "Show disabled devices" to reveal hidden recording devices.
5. Locate "Wave Out Mix," right-click on it, and choose "Enable."
Once you've enabled Wave Out Mix, your audio recording functionality should work similarly to how it did in Windows XP...