Hello Jürgen Daseking,
Thank you for reaching out to the Microsoft Q&A Forum! I understand that you’re ready to upgrade to Windows 11 (great decision!). The message “The assistant is already running” usually means a previous upgrade attempt left some files or processes behind. The easiest way forward is to use the official ISO method, which bypasses the Assistant and gives you a clean upgrade.
Please make sure your Surface has 25–30 GB free space to proceed.
1 - Download Windows 11 ISO from Microsoft official site (choose your language and click 64-bit Download).
2 - Mount the ISO and open setup.exe.
3 - When prompted, select Keep personal files and apps (recommended).
4 - Follow the on-screen instructions.
5 - The process will restart your device several times.
After completion, check Settings → Windows Update for any additional updates. I look forward to receiving your update. Let me know if you need further assistance, feel free to ask me by clicking "Add Comment". Thanks for your effort.
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