Want to run two accounts at once (e.g. AFK coins on one, farm on the other)? Sandboxie is the simplest way. One of several methods.

Steps

1. Download and install Sandboxie if you don't have it.
2. Right-click the Core Fiesta icon and choose Run Sandboxed.
3. In the dialog, pick DefaultBox, tick Run As UAC Administrator, then OK.
4. The launcher opens with a yellow frame (Sandboxie is active) - log in with your first account.
5. Now open Core Fiesta again normally (double-click, without Sandboxie) - no yellow frame.
6. Log in with your second account.

Both clients now run at the same time. If Sandboxie breaks after a patch, see Fix Sandboxie.

Original guide by HyperSpace on the Core Fiesta forums.