EA announced its Origin service will drop support older operating systems in August 2016. What it boils down to is that everything older than Windows 7, so basically Windows XP and Windows Vista, will no longer be able to enjoy the full features of Origin.
Windows XP and Vista users will still be able to play their current games but they will no longer be able to download new games, view achievements, or use Origin's social features. More details can be found at the EA Support website.
Origin no longer supports Windows versions earlier than Windows 7. If you're running Windows Vista or older, you'll still be able to play your games, but you’ll need to upgrade your OS to enjoy all Origin has to offer.
What you'll still be able to do:
Play your current games
Make in-game purchases
Visit the Origin Store online
Change your account settings online
(Origin Access members) visit and add games from The Vault online
What you will not be able to do anymore:
Use the Store tab to browse and purchase new games (and The Vault, for Origin Access members)