By default, the Zune software is set to keep 3 episodes of each podcast (not counting items marked In Collection). You can set the software to keep 1 to 10 or even All of the podcast episodes. Here’s how:
1. Open the Zune software.
2. Go to the upper right corner and select Settings.
3. In the left column, click PODCASTS.
4. Under Keep, use the slider to select the desired number of podcast episodes to keep.
5. Click the OK button.