New
#11
M$ has removed the update offer because there are many people complaining about many issues on Ver 2004.
Known and Resolved issues for Windows 10 May 2020 Update version 2004
As you have a full backup you can try ver 2004. Download the Win 10 2004 iso, mount it and run setup.
If I were you I would install Win 10 1909 that has been polished and works well. If you don't have win10 ver1909, you can download from MS using Heidoc tool, then mount it and run setup.
(The Win 10 1909 iso downloaded from MS using Heidoc tool, has sources\install.wim bigger than 4G, so to transfer to a Fat32 USB drive you have to split it to smaller install.swm files. Have a look at split.zip)