UnityFree Licensing issue

On running Unity 4.3.4f1 and choosing to activate the free version, a License issue is detected: “There was a problem validating the license because the Operating System identification seems to have changed”.

Deleting the .ulf file as per Known Issues #3 doesn’t seem to help, nor does running it as the administrator, and uploading the 2kb file for manual activation returns the message: “Upload failed: License is missing client information”

After downloading an apparently corrupt installer 4 times, its starting to feel like just booting up Unity might be more trouble than its worth :frowning:

There was a problem validating the license because the Operating System identification seems to have changed.[SOLUCION]

Lo que se debe de hacer es ejecutar Unity como administrador y aparecera la ventana de activacion…
Y listo…

What you should do is run Unity as an administrator and activation window will appear … And presto …