Microsoft Windows HRESULT Error Code 0x800700EF: How to Fix It

Q: What does error 0x800700EF mean?

It means an operation is not allowed while you are in fullscreen mode. You need to exit fullscreen mode or close the fullscreen app.

Q: Can I fix error 0x800700EF without restarting my computer?

Yes, usually just exiting fullscreen mode or closing the fullscreen app via Task Manager resolves the issue without a restart.

Q: Why does error 0x800700EF occur during installation?

It occurs if you try to install software while a fullscreen application is running. Close the fullscreen app and try the installation again.

Q: Is error 0x800700EF a sign of malware?

No, it is not typically malware-related. It's a Windows system error triggered when a fullscreen app blocks certain operations.

Q: How do I prevent error 0x800700EF in the future?

Always exit fullscreen mode before performing system operations or installs. You can also run resource-heavy apps in windowed mode when multitasking.

Abstract

Error code 0x800700EF, also known as ERROR_FULLSCREEN_MODE, indicates that an operation is not allowed while an application is running in fullscreen mode. This typically occurs in Windows when you try to perform a system operation (like opening File Explorer, running a command, or installing software) while a fullscreen app (such as a game or video player) is active. The error is usually easy to resolve by exiting fullscreen mode or restarting the app.