On the GUI installation, the following error appears on starting the «Windows Install» stage:
«Setup failed to install the product catalogs. This is a fatal error. The setup log files should contain more information.»
(Español: «El programa de instalación no puede instalar los catálogos del producto. Éste es un error grave. Los archivos de registro de la instalación deben contener más información»)
On clicking Accept, the log appears, containing amongst others, an error about:
«Error: The signature for Windows XP Professional Setup is invalid. The error code is 80096001.»
(Español: «Error: La signatura del programa de instalación de Windows XP Professional Edition no es válida. El código de error es 80096001.»)
If you close this dialog, the system will immediately restart.
While this can have other causes, in my case it was because I was using «ProfilesDir=D:Usuarios» in my unattended setup to relocate all the user data to another partition, and forgot to format D: in the script.
As a quick fix, I opened a terminal with the handy (and obscure) Shift+F10 shortcut, did a «format /fs:ntfs /q D:», and restarted. And so did the installation, which finished correctly.