Microsoft Internet Explorer offers the AutoComplete feature to remember past entries and automatically pre-populate fields as you type to save you some time and effort. You may find it quite convenient, but having AutoComplete remember username or password information can pose a security risk.
Members of the Administrators group typically have full control to modify registry keys. Unwittingly executing a malware-infected or other questionable program with Administrator privileges can result in registry additions or edits which may adversely affect the system. To safeguard the registry without logging out you can use this trick.
Windows creates hidden Administrative Shares at the root of each drive and to the system root folder to allow administrators to remotely access the data. If a server or workstation will not be administered remotely or has no need for the Administrative Shares though, they should be removed so that they don't provide a potential attack vector for a hacker or malware to enter the system.