How to disable turn off computer button in the welcome screen ?

By default, there will be turn off computer button in the buttom of the welcome screento disable turn off computer buttom in the welcome screen, follow the following instruction !
1. Logon as an administrator in ur computer.
2. click on start then Control Panel

3. Click Performance and

maintainence

4. Click Administrative Tools

5. Double-Click Local Security Policy.

6. Expand Local Policies by clicking the plus sign next to it, and then click security options

7. In the right pane, double-click the shutdown: Allow system to be shut down without having to log on policy.

8. Click disable than click on OK.

now windows XP will remove turnoff th computer : option from the welcome screen!