I have windows 8.1 pro x64. This is a company PC so some option has update frequencues are handled remotely, but I had no issue installing the old version, and the message seems not related to that.

While you are fixing this, why do not evaluate the opportuinty to release zorro as a zip file i.e. no installer. This will allow easier multiple instance installation i.e. one for one for production and one for test on the same computer.

Thank you