No. Scrivener is a standard file-based computer program, not a web-based or mobile application. This means that any projects you create in Scrivener are saved outside of the program, on your hard drive. They are not kept within Scrivener itself. This is similar to the way Microsoft Word works, in that you can keep .DOCX files on your computer even if you don't have Word installed. Thus, upgrading, uninstalling, or even switching from trial or beta versions of the program to the purchased version, will not affect the work you've done so far.