Win8.1 subscription upgrade Win10 failed solution

Win8.1 subscription to upgrade Win10 failed solution:

There are users to download the temporary folder Win10 installer "C:\\$Windows.~BT\\” (hidden system files After copying to other partitions, start the setupre.exe program in the source folder to perform normal installation.

Note: If your <quo;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.

Tips: $Windows.~BT” folder in some cases where the content will disappear, which has a lot to do with its "temporary" attribute, the root cause of this problem lies in The system believes that the file in the folder has been “completed the mission”; therefore, the content will be deleted, but from the feedback of “Installation Failure”, this is obviously a serious mistake. Therefore, in order to prevent the abnormal problem caused by this folder property problem, you can consider putting the files in the copied folder into the normal folder or changing the folder properties after copying. Remember, don't make any changes to the original “$Windows.~BT” folder to avoid affecting the normal upgrade channel.
▲The original 6GB or more folder is only 140MB inexplicable

The above is the introduction of the Win8.1 subscription upgrade Win10 failure solution, friends with this problem can understand.