Just change the link from the icon from harbinger.exe to harbinger.jar (JAVA-installation is needed).

To be able to run Windows native version of the game on Windows XP, you have to use an hex file editor (utility wich is able to edit internal content of any file).

- search this hex value 0002000006 within the file
- the byte's value 06 (hex address in the file: 140) must be changed to 04
- after 7 bytes, the next byte's value 06 (hex address in the file: 148) must also be changed to 04
- save changes

XP is now able to run "harbinger.exe"

Don't forget to make a backup of the file.