Perform a System Restore:
If you’re having problems installing Windows Updates, use the following method.
When you start your computer by using the Windows installation disc, you can perform system recovery options on start up. To do this, follow these steps:
Turn off your computer manually by pressing the power button.
Start your computer by pressing the power button.
At the log on screen, tap or click the power icon in the lower-right corner.
Press the Shift key, and then tap or click Restart.
On the Choose an option page, tap or click Troubleshoot, and then tap or click Advanced options.
Tap or click System Restore. The computer will restart to System Restore. Select your account to continue.
On the System Restore page, tap or click Next.
If you are prompted to specify a disk to restore, select the hard disk, and then tap or click Next.
When the restoration process is complete, tap or click Restart.
If you are still facing the issue, visit theis website
https://www.errorsolutions.tech/error/windows-update-error-code-80070103/