By 2008, the complete English version, Encarta Premium, consisted of more than 62,000 articles, numerous photos and illustrations, music clips, videos, interactive content, timelines, maps, atlases and homework tools.
Microsoft published similar encyclopedias under the Encarta trademark in various languages, including German, French, Spanish, Dutch, Italian, Portuguese and Japanese.
Thanks for adding those details. The edition list and article count you gave match what the earlier reply left out: Encarta Premium 2008 is the last complete English edition, and Microsoft's localized versions covered several other languages. I can't confirm the 62,000-article figure from here, so I'd check it against Microsoft's own product pages or an archived copy of them before quoting it.
If you want to go further, the Wayback Machine keeps captures of Microsoft's old Encarta pages, which would show how the product was marketed in its final years.