Q: How can I be sure to keep TV content on my iPod even after I have viewed it and removed it from my iTunes folder on my computer?
A: There are a few different ways that this can be handled. The simplest method is to set your iPod to manually manage its content and then drag-and-drop your music and video content onto your iPod from iTunes manually, and remove it from your iPod manually when you’re done with it.
This mode is enabled by connecting your iPod and selecting it in the iTunes source list on the left-hand side. From the main “Summary” screen that appears, simply check the option labelled Manually manage my music and videos and click the “Apply” button.
Once in manual mode, changes made in your iTunes library will not be automatically reflected on the iPod itself—you will have to add tracks to your iPod manually by dragging them from the iTunes library to the iPod icon on the left-hadn side, and remove tracks by expanding the iPod within iTunes and browsing through it directly (from within iTunes).
This of course means that you can remove content from your iTunes library and it will not be automatically removed from the iPod. In fact, nothing will be removed from the iPod unless you manually delete it yourself (although even in manual mode, certain types of content, such as podcasts, can still be synchronized automatically).
Unfortunately, manual mode applies to both videos and music, so this may not be desirable if you want to continue to synchronize your music to your iPod automatically.
If you want to keep using automatic synchronization but are concerned about videos taking up unnecessary disk space on your computer, the other workaround is to simply remove the underlying video file from your computer, but leave the entry in your iTunes library. iTunes will never remove content from your iPod as long as it remains listed in your iTunes library, regardless of whether or not the underlying file actually exists or not.
The fastest way to access the underlying file is to right-click on a video track in iTunes to bring up a contextual menu, and then choose the option to Show in Windows Explorer (Windows) or Show in Finder (Mac). This will open an Explorer/Finder window with the current track’s actual file highlighted. From there you can simply delete the file or move it to offline storage. iTunes will complain about the file not being found if you later try to access it from within iTunes, but it will not be removed from your iPod itself as long as the entry remains in the iTunes library.