First you will want to be sure you are logged in as an administrator.
1. Begin by right clicking on on “This PC” icon from any windows explorer window, then left click on Manage
2. Expand Local users and groups, select users folder, then the Guest account on the right hand side.
3. From here you can choose to delete the guest account by right clicking on the guest account and then selecting delete or go to properties and then check the
box that disables the account.