No, it doesn't support multiple monitor display.

Yes. Please uninstall the demo version first before installing the full version.

It is possible that there are input typos when you entered the registration code. We suggest you copy the license code and paste it onto the registration entry area directly to avoid any confusion such as “0” and “O”, “I” and “1”.

You can download the newest DirectX 9.0c End-User Runtime driver from Microsoft download Center. http://www.microsoft.com/downloads/

Your account is established and a download password is sent to you immediately after RegNow informs us of your purchase. However, there could be a delay from RegNow to inform our system to issue you the download account and password. The entire process may take 20 to 40 minutes.
If you still have not received your password after one hour, please contact digifish@formosoft.com and include your registered e-mail address.

These are some suggestions:

1. Choose a lower display resolution.

E.g.: From 1280x1024x32 to 1024x768x32

2. Switch your color resolution from millions to thousands colors.

E.g.: From 1024x768x32 to 1024x768x16

3. Reduce the number of fish.