Downloading videos onto the iriver E100

Software / Media Transfer The E100 comes packaged with a disc containing iriver plus 3 media player, firmware updater, video converter, and Windows Media Player 11. If you have owned an iriver player, you are familiar with this software with the included iriver media player. This is a standard media player much like any other but has a few features catering to the iriver family of players, such as a firmware updater, ebook txt manager, and video converter. This media player is a bit different from Windows Media Player but still is straightforward and easy to use. If you don’t care for iriver’s media player you can always use any other MTP based media player to manage playlists and load your E100 since also included on the disc is a video converter and firmware updating utility.
If you don’t like to use media players to transfer the E100 will allow you to select either MTP or MSC transfer mode. This means it is drag and drop and also compatible with any OS. Drag and drop will work fine in MTP mode as well, but only if you are using Windows XP SP2 or Vista.

and the difference between e10 / e100 your guess is just as good as mine