Clearing the last user logged on

Every time a user logs into your computer, their username is stored, and that name is displayed the next time the classic logon screen is displayed. This can be a nice feature, but it also can be a feature that causes a security problem. Knowing a user’s username is half the battle of breaking into a computer. If you have sensitive information on your computer, follow these instructions to hide the last user logged on:
1. Start up the Registry Editor again by clicking the Start menu and selecting Run. Then type regedit in the box and click OK.
2. Navigate through HKEY_LOCAL_MACHINE, SOFTWARE, Microsoft,Windows,
CurrentVersion, policies, and system. Locate the DontDisplayLastUserName entry.
3. Right-click the entry and select Modify. Then type in a 1 to activate the feature, as shown in Figure . Click OK, and you are finished.

If you ever want to reverse this hack, just repeat the instructions above and replace the 1 with a 0 for the value of DontDisplayLastUserName.