Hi,
Thank you for writing to Microsoft Community Forums.
I understand that pressing F4 closes all the windows on your computer. I’ll certainly assist you with the issue.
However, please let us know:
- Are you aware of any changes made to the computer prior to this issue?
- What is the make and model of the computer?
- Which build version of Windows 10 is installed on the computer? Refer Which version of Windows operating system am I running?
I suggest you to perform a clean boot on the computer and see if that helps.
Performing a clean boot will start the computer with minimal set of drivers and programs, to determine whether a background program is causing the issue. Some of the Startup programs will not load after performing a clean boot on the computer. However, that functionality will return when you reset the computer to start normally after finishing the troubleshooting.
To perform a clean boot on the computer refer to the article How to perform a clean boot in Windows.
If performing a clean boot fixes the issue then, please refer to the section How to determine what is causing the problem after you do a clean boot to check which program is causing the issue.
Note: Please refer the section Reset the computer to start normally after clean boot troubleshootingto boot the computer in to normal mode after troubleshooting.
Let us know how it goes.
Regards,
Nikhar Khare
Microsoft Community - Moderator