What is a system file?
A system file is any file on your computer that’s essential for running Windows. System files are usually found in the Windows folder or the Program Files folder.
System files are hidden by default. It’s best to keep system files hidden to avoid accidentally modifying or deleting them. If you need to view your system files
Show hidden files
Here’s how to display hidden files and folders.
Click the View tab.
Under Advanced settings, click Show hidden files, folders, and drives, and then click OK.
Normally, you shouldn’t change system files by renaming, moving, or deleting them because doing so could prevent your computer from working properly. Even if changing a system file doesn’t seem to have an immediate effect on your computer, the next time you start Windows or run a particular program, your computer might not work correctly.
If there are system files on your hard disk that aren’t needed, you can use Disk Cleanup to safely delete them.
If you need to make changes to your system, you should use a tool designed for that task. For example, to remove a program from your computer, use Programs and Features in Control Panel. To learn how to do this, see Uninstall or change a program.