How to view FAT32 Ubuntu files from Windows 10?

I installed Ubuntu 16.04 on my PC a while ago, and I really like the new OS. I've noticed that I can access all data on the hard drive from Ubuntu, but I can't find Ubuntu files from Windows. I set up Ubuntu with the FAT32 file system (yes, I know), which is supported by Windows, and no partitions are encrypted. If anyone can tell me how I can allow Windows to view the files on the other partition, that would be great. If I could do this without a third-party application, it would be even better.

Here's what my disk manager sees: https://i.stack.imgur.com/Tgi22.png

You seem to admit this in your question, but using FAT32 is not a good idea for installing your Ubuntu system. It doesn't even have basic security features expected by Linux.

It is better to set up a system partition for each OS using an appropriate filesystem for that OS, and then have a separate partition which is to be shared by both OSes. While FAT32 is an option for such a partition, NTFS is probably a better choice now as FAT32 still has that 4GB file size limit, very relevant these days, and it's a little easier to corrupt if your computer doesn't shut down cleanly. NTFS is now supported well by most operating systems, including Linux.

That said, I don't know why your FAT32 partition isn't showing on Windows. That may be a Windows issue that you'll need to sort out, if you do want to continue trying this.