Updating hard drive
Microsoft is blocking the update on PCs that have a USB hard disk like a thumb drive attached, or machines with an SD Card in the SD Card reader.
There you have a few simple ways to bring our Hard Disk back if it disappeared after you made the updated your Windows 10 system.
Still, it’s strange that Microsoft only detected this USB storage issue late in the May 2019 Update, when it has millions of Windows 10 testers helping flag issues like these.
If you are on a laptop or Windows tablet with a smallish hard drive, then you might be running low on disk space after installing the latest version of Windows.
If you want to be extra safe, then you should create a system image of your computer so that you can recover all your apps and settings, along with your other important files when needed. On your Windows PC, search "backup" Backup and Restore (Windows 7) and then click on ‘Create a system image’ option from the sidebar. Now choose where you want to save the backup image. Click the Start backup button to start the backup process.
It is recommended that you choose an external hard drive for backups. Cumulative updates on Windows 10 are mandatory, they are no longer optional.