The following tips will help you to win these games:
1. Start the registry editor. (Run, type 'regedit')
2. Move to the key HKEY_CURRENT_USER\Software\Microsoft\Windows\ Currentversion\applets\Hearts
3. Create a new string value named ZB, fill with 42.
Now run the game. Press Ctrl + Alt + Shift + F12, then all your opponents cards will be seen clearly.