Welcome Will,
Thanks for reaching out to Microsoft Q&A Forum. I understand that Call of Duty shows a File Write Error with code 0x00001338 on Windows 11, even though you have already tried many fixes.
To help narrow this down, could you please answer these questions:
- Which Windows 11 problem do you need help with: file writing or storage on Windows itself, or only inside the Call of Duty game?
- Do other apps or games on the same PC also fail to save or write files? Or does the error happen only in Call of Duty?
Once I have your answers, I can check whether this falls within what I can help with on Windows 11.