A user is having trouble using the PDF merging tool from PDF24 without having to register or install. Although the description makes it clear that no registration or installation is needed, the user seems to have problems accessing or using the tool without going through these steps. This is particularly problematic as the easy handling and accessibility of the tool are key features of its functionality. It is unclear whether this is a technical error or a misunderstanding in usage. The problem requires investigation and resolution in order to make the tool effective and accessible for all users.

To solve the problem, the user should first open the PDF24 Merge Tool link in a common web browser. No registration or installation is necessary, as the tool is browser-based. The tool then opens on its own page, where the user can add his PDF files using the drag-and-drop function. The selected files can be arranged in the desired order and checked before the final merge. After confirmation, the tool starts the merging process to create a single PDF document. The completed document can then be downloaded directly. By considering these steps, the tool can be used as intended, free from registration and installation.