Run Windows Update Troubleshooter
Windows 10 includes a troubleshooter that can automatically detect and attempt to fix issues with updates and patches. If you're uncertain about the issue and what to do next, run this troubleshooter. While it may not always find a solution, it's a first step in error resolution.
Step 1: Go to the search box and type Troubleshoot. Select Troubleshoot in System Settings.
Step 2: In the Troubleshoot window, the first item at the bottom is 'Get up and running.' Choose Windows Update.

Step 3: The 'Run the troubleshooter' button will appear, and you select it to initiate the troubleshooting process.
Step 4: The troubleshooter window starts scanning to check for any issues. If found, it automatically searches for missing updates to corrupted files. The troubleshooter will ask if you want to apply the fix or skip it.
After scanning, the troubleshooter presents a list of detected issues and their resolutions. Then, try updating Windows 10 again.
Insufficient Drive Space
The 32-bit version of Win 10 requires 16 GB of free space, while the 64-bit version needs 20 GB. Win 10 also reserves 7 GB to ensure enough space for most installations. If your drive is full, free up space by uninstalling large programs and ensuring you've backed up essential files and installations. You can reinstall them once Win 10 is stable.

The quickest way is to uninstall space-consuming applications, ensuring you've backed up essential files and installations. Afterward, you can reinstall them once Win 10 is stable.
Organize file deletion in the following order: video files, audio files, image files, document files, and other files. Easily back up unwanted files to an external hard drive like USB. Then, run the cache cleanup program and other storage-consuming tasks.
ISO Image Error

If you install Win 10 using a corrupt virtual drive or bootable USB, the file might be damaged, leading to installation failure. Alternatively, hardware issues or a faulty virtual drive/USB creator could be the cause. To fix this, redownload the ISO image file and use a different drive/USB creator.
Error Code Appears
During installation, the program may halt, displaying an error code. There are hundreds of possible error codes, indicating underlying issues. When facing this error, note the code and search the internet for troubleshooting solutions. Here are some steps you can take if a reliable solution isn't found.

Here are some steps you can take if a reliable solution isn't found.
- Disconnect all unnecessary hardware connections from your computer, leaving only the screen, mouse, and keyboard.
- Remove all unnecessary internal hardware connections such as the graphics card, external hard drive, etc.
- Uninstall unnecessary programs before installation, such as antivirus software, game driver controllers, etc.
- Turn off Hibernate mode by going to Command Prompt and typing “powercfg /h off”.
- Choose the Win 10 options and keep personal files intact by selecting Custom: Install Windows instead of Upgrade.
Incompatible Hardware
If your computer has a processor below 1 GHz or RAM under 2 GB, you won't be able to install Windows 10.
Hope the shared tips here help you identify and resolve installation issues with Windows 10. Best of luck!