At some point, Microsoft (MS) is going to republish their v1809 Upgrade and folks then will be faced with HOW to do that Upgrade -- SAFELY. By this term, I mean the following: upgrading your PC to the new version while not corrupting or losing anything in the process and being able to Rollback to your current version if anything goes wrong.
Unfortunately, the most common method for doing this -- Windows Update -- is also the most unreliable. When it fails, and it often does, you run the risk of your PC being left in a corrupted state such that, even if it does boot (and often, it does not), some functions don't work properly. And like with Windows Update, the MS built-in Rollback function tends to be unreliable and not work properly.
So, HOW do you prevent this problem -- by doing two things described below: (1) performing an Image Backup of your PC so that you have something to restore FROM, (2) performing a Repair-Install to do an in-place Upgrade using Win install media, instead of using Windows Update.
---------- Image Backup ----------
One of the most well-known and reliable tools for performing an Image Backup is the FREE version of Macrium Reflect.
What I recommend is the following:
1) Download and install Macrium Reflect (MR) from here: http://www.macrium.com/reflectfree.aspx
2) Run MR and choose the option: "Create an image of the partition(s) required to backup and restore Windows" to write a full backup to an external drive or USB stick. NOTE: If you have a separate DATA partition, this will NOT create a backup of that because that partition is not involved in running the OS. You have to select that IN ADDITION to the ones that MR selects to have it included in the Backup.
3) Use the option to create a boot USB stick or CD -- will need this later if you have to do a Restore from the image you created.
My experience is that MR, when using the High Compression option, typically can compress the saved image file to about 50% of the USED space in the OS partition. This means if you have an 80GB OS partition, and 40GB is used, MR only needs about 20GB to store the image file.
I use this all the time and it typically takes less than 15 minutes to do the image backup and about the same time or less to do a restore.
NOW, you have the means to restore a full working system from the external drive or USB stick in only a few minutes.
---------- Repair Install ----------
This install only overwrites the Windows system files and leaves the user settings, user data, and any installed applications intact. It is essentially doing an in-place upgrade over the top of the existing Windows installation.
You do this as follows:
1) Using this link, download and create Win10 install media using a USB stick or DVD: Windows 10 download
NOTE: when you go do download and build install media, the tool defaults to matching what is already installed on your PC (as in, Home for Home, 64-bit for 64-bit). Make sure you select the same version as needed for your PC. If you do not, the resulting media will be different and will force you to enter a NEW product code!
2) Insert the Win10 media into your PC -- do NOT boot from it. IF you BOOT from it, that will erase everything you have and do a Clean-Install, not a Repair-Install.
3) Follow the instructions in this Win10 Community Forums thread: http://www.tenforums.com/tutorials/16397-repair-install-windows-10-place-upgrade.html
NOTE: This can take quite a while to do, with current times ranging from 30 minutes for a fast SSD, to 90 minutes or more for a standard Hard Drive. Your PC will REBOOT several times during this process, so expect that to happen.
When it is nearly finished, your PC will reboot and you will see the "Hi" on a black background. At this point, you are only a few minutes away from seeing your desktop again -- with the new OS version installed.
---------- Restoring the previous setup ----------
If something goes terribly wrong and you do not get to the desktop with the new OS version installed, since you made an Image Backup, you can restore your working PC from it.
Follow these steps to do that:
1) Insert the MR Boot Media you made above
2) Reboot your PC, pressing F9 repeatedly in order to get a Boot Devices menu. If you do not see that menu directly, then press the Esc key repeatedly to get the Utilities menu, and when that displays, select the option shown there for the Boot Devices menu.
3) Once that menu appear, select the USB or DVD drive containing the MR Boot Media
NOTE: This can take a LONG time (i.e., several minutes) to complete the boot process. So, don't get impatient and interrupt the reboot
This link from MR explains how to do a Restore using the MR Boot Media you made previously: http://reflect.macrium.com/help/v5/how_to/rescue/rescue_a_system_with_the_windows_pe_environment.htm
When this is done, you restart the PC as the instructions indicate, remove the MR Boot Media, and you should then reboot directly into your previous working OS.