You can open only one project at a time. (However, you can add media from one project to another.) To ensure that Adobe Premiere Elements can open an existing project, make sure that both the project file (.prel) and the source files used in it are accessible on your computer.
Do one of the following:If Adobe Premiere Elements is not open, start Adobe Premiere Elements and, from the Welcome screen, click the project name. (If the project isn’t listed, click Open Project, select the project file, and click Open.)
If Adobe Premiere Elements is open, choose File > Open Project or Open Recent Project; then select the project file, and click Open.
In Windows®, double‑click the project file.