This error may cause if there is any third party program/app is blocking the installation.
If you have connected any external devices other than mouse and keyboard, then I would suggest you to disconnect and check.
Place the computer in clean boot state and then try to install Windows 8.1 and check if the issue persists. Clean boot will help you determine which third party program or app is causing this issue.
If you have installed any security software, then try disabling it and check if it helps.
Run the Windows Update troubleshooter below, and then run Windows Update again. To start the troubleshooter, clickrun now
If the problem continues, use the System File Checker tool to repair damaged Windows files. To do this, follow these steps:
If the problem continues, use the Deployment Image Servicing and Management (DISM) tool to fix Windows Update corruption errors. To do this, follow these steps:
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