(This tutorial on realizing manual update is universally applicable! Including those Vista users who do not want to temporarily close Vista UAC to auto-update!)

Prefer auto-update to manual-update? Vista users please view [Vista Users] How to Disable Vista UAC and Complete Auto-update while users of others OS please simply double-click on the game launcher on your desktop

The illustrated steps below will lead us to the fantastic world of Chaos Online.
Go to http://co.enjoymmo.com/, scroll down, download the following patch-file

Repeat the above process for other patch-files listed on the webpage

Prefer auto-update to manual-update? Please view [Vista Users] How to Disable Vista UAC and Complete Auto-update