Model/Order number: WDAVP00BE
Actually, that’s a Gen1, not a Gen2.
Your best bet would be to download
and then run MKVFix to automatically scan your media.
Pretty pictures for using MKVFix here: http://community.wdc.com/t5/WD-TV-HD/where-can-i-find-older-software-for-HD-MEDIA-PLAYER-Gen1/m-p/86339