Hi Timo.
Thanks for your post in Microsoft Community.
In your description, you are having problems installing the X-box app on your computer with error code 0x80073d05. even though you have tried sfc system check, deleting cache, updating Microsoft Store, even reinstalling Microsoft Store, etc., nothing has resolved the issue. Your efforts are worthy to be recognized. And the error code 0x80073d05 is usually because you have some residuals from uninstalling certain software before, which causes you to get an error during the subsequent installation.
In order to solve this problem, you can try the following options, first of all, create a new account:
Please create a new test account, and switch to the newly created account to see if You can download X-box applications as normal. This troubleshooting step can help isolate the This troubleshooting step can help isolate the problem due to an invalid profile configuration.
Create a local user or administrator account in Windows - Microsoft Support
If you still can't download the X-box apps in the new account, then it seems that we can only proceed with resetting the computer. However, before you reset the computer, we can first try some system override installations, which are less impactful to the system (see the link below).
Disclaimer: At this point, we have exhausted all troubleshooting and I recommend that we try to perform a clean install to get your computer back into a Please ensure that you backup any important data, including Documents, Pictures, Videos, and more. After that, you can find instructions on how to install Windows 10/11 in the following article by MVP Andre: How to: Perform a Custom Installation of Windows 11 and Windows 10 or - Microsoft Community
If the problem is still not solved after overriding the installation of the system, then we can only try to solve the problem by resetting the computer.
Note that before you reset your computer, make sure you have a good backup of your data to avoid data loss.
Please refer to the following steps to reset your computer:
1 Select “Start” > “Settings” > “System” > “Recovery”.
2 At the “Reset this computer” side, select “Reset computer”. Then select from the options and/or settings in the table below.
3 You can try to turn on “Keep my files” during the reset process, if you still can't install X-box apps after keeping the files and resetting, then please reset again and delete everything.
I hope the above can help you, if you have any other questions please continue to contact me, thank you for your support and understanding.
Best regards,
Zev - MSFT | Microsoft Community Support Specialist