Win10 upgrade slow how to do

Microsoft said that on some computers, upgrading and installing win10 may take more time, sometimes even more than 24 hours, but as long as no error, this is normal.
According to the experience of netizens, there are mainly three places in the win10 upgrade process that will last for a long time:
1, black screen blue circle stage, 30-39% progress time, need to download Windows 10 Dynamic update.
2, 96% progress, the system is busy backing up your data.
3, the last prompt message "Let's take longer to set up your device, but will soon be ready".
Correspondingly, Microsoft also gave some tips for reference.
1, first make sure your computer is fully compatible with Windows 10. The new system requirements are very low, but it is clear that the high configuration update, installation, and running speed will be much faster, it may take 20 minutes, the old computer is not allowed.
2, disconnect all unnecessary USB devices during the upgrade process. The keyboard and mouse can be retained, but can be temporarily removed during the stage where input and control are not required.
3, if there is a display extension cable, it is best to unplug it first. Microsoft said the move could significantly speed up downloads.
4, if more than 24 hours have not been completed, then patience, etc., or find a master, go online to check the relevant situation, or try a new installation.
The second and third estimates are not noticed by many users, but the results are the most immediate, so remember to try.
Additionally, if your original Windows 7/8.1 system has been used for a long time, and the program and data are many, you must clean it up in advance.