By disabling the Guest account, people cannot use it to log on to your computer, including yourself. If you insist on disabling it, there are three methods in total for your option.
Method 1: Disable Guest account in Computer Management.
Step 1: Open Run dialog box by Windows+R hotkeys, type compmgmt.msc and tap OK (or press Enter) to open Computer Management.
Step 2: Find and open Users folder.
In Local Users and Groups, you can locate it immediately.
Step 3: Right-click Guest account on the right and choose Properties in the context menu.
Step 4: Check the box before Account is disabled and click OK in the Guest Properties window.
Method 2: Disable Guest account in Local Group Policy Editor.
Step 1: Access Local Group Policy Editor.
Step 2: Follow the path of Computer Configuration/Windows Settings/Security Settings/Local Policies/Security Options to locate and open the "Accounts: Guest account status" policy.
Step 3: In the policy's Properties window, select Disabled and tap OK.
Method 3: Turn off Guest account in Control Panel.
Step 1: Open Search bar by Windows+F hotkeys, enter guest account in search box, choose Settings and click Turn guest account on or off.
Step 2: Select Guest account in Manage Accounts window.
Step 3: Click Turn off the guest account in the next window.
Tip: If you find it necessary to enable this account again, you can refer to 3 Ways to Enable Guest Account in Windows 8/8.1.
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