Problem installing ModKit Link - 'Are you sure you want to cancel the installation?'

We’re having trouble installing ModKit Link on our Windows 7 workstations. After starting installation, and clicking ‘Install’, we’re instantly presented with a message saying ‘Are you sure you want to cancel Modkit Link installation?’. If we click ‘No’, it just goes back a step and when we click ‘Install’ it presents the same message. Anyone have any ideas how to get around this?

Thanks.