Please note that there is no problem with your booking or download upgrade. The upgraded version is not corrupted as some say, you will be notified in the next few days or weeks when your device is ready to be upgraded.
If you are very eager to upgrade, users of tech knowledge provide the above message to modify the following registry key to install immediately.
Warning: Serious problems can occur if you modify the registry error. There was a problem with the previous modification and backup of the registry for recovery.
1: Find the registry key: [HKEY_LOCAL_MACHINE SOFTWARE Microsoft Windows CurrentVersion WindowsUpdate OSUpgrade]
2: It should exist, but if not, create it to create a new DWORD (32-bit) value named AllowOSUpgrade.
3: Create a new DWORD (32-bit) name value = “ AllowOSUpgrade " (without the quotation marks), and set the value = 00000001.
Once the registry key is modified, close and reopen the desktop control panel, go to Windows Update and check for updates. You should now be able to click the Start button and upgrade to Windows 10. Note: 8.1 Windows users must go to the desktop control panel instead of the modern Windows Update UI.
But now the new problem is coming again, that is the installer It claims to be missing the boot.wim file and cannot be installed.
In this regard, we can double-click the downloaded setup in the source folder by copying the downloaded win10 system temporary folder <;C:$Windows.~BT” (hidden system folder) to other disks. The exe program is installed;
Note that if your "C:$Windows.~BT” folder is not complete, it is likely that the download has not been completed. Note the Windows Update ID on the right side of the taskbar. If it exists and prompts you to download the percentage of updates, you should not do this. After the prompt disappears, entering the folder will reveal that the contents of the file are very similar to the Win10 system image.
But some users also said that the "Windows.~BT" folder will disappear in some cases, which has a lot to do with its "temporary" attribute. The root cause of this problem is that the system believes that the file in the folder has “completed the mission”; therefore, the content will be deleted, but from the feedback of “Installation Failure”, this is obviously a serious mistake. Therefore, in order to prevent the abnormal problem caused by this folder property problem, you can consider putting the files in the copied folder into the normal folder or changing the folder properties after copying. Remember, don't make any changes to the original “$Windows.~BT” folder, so as not to affect the normal upgrade channel