Kernel freezes during the booting process.
While booting from DOS, the computer freezes during the load of the driver aspi7dos.sys in config.sys. This is why e.g. Linux performs automatically a controller reset at booting-time, to set up again any already set values. This works, but possibly it is not always reliable. When the error appears under DOS, you can order the controller to reset the aspi7dos.sys driver. However we advise not to do so, because then the controller is possibly not correctly initialized anymore.