First, you are replying to a two-year old thread, with a related though not the same question. This is considered bad form, you really should start a new topic.
Secondly, I'm not sure what you mean by "development environment for visual modelling"? The OutSystems Platform? You can find here what the system requirements are (Google is your friend!). As you can clearly see there, neither Windows 7 nor SQL Express edition are supported.