Relic want owners of the original game to switch over to the new Steamworks version of the game prior to the migration on May 7th, at which point all the old versions of the game will stop working:
”You will continue to have access to the previous version of Company of Heroes until the Quazal server closure, and thus have the option of being able to play either the Steam or Quazal version of the game until that time,” according to a post on the official forums.
If you bought the game over Steam, you should already have a new entry in your Library called ’Company of Heroes (New Steam Version)’, which is the Steamworks version of the game. Download that, and continue to play as normal.
If you didn’t buy Company of Heroes or any of its expansions via Steam, you can input your CD Keys into Steam, which will grant you access to the new version. Make sure to input your expansion keys as well, as they have now been bundled into a single entry via the ‘DLC’ Properties tab.
Speaking to Strategy Informer, Game Director Quinn Duffy mentioned that this migration was an expensive process to be engaging with, especially during the development of Company of Heroes 2:
“We’re moving Company of Heroes to Steam because we’re losing our servers from Quazal. That’s expensive and it’s time-consuming, you know in the middle of making the new Company of Heroes, to keep that thing alive.”
For more information, check out the official forum post, and make sure you get it done before May 7th!