Let's try to remove Windows XP SP3 using the Control Panel again:

1) Close any programs that you are using > [Start] > Control Panel.

2) Click Add or Remove Programs to launch the installed programs list. Click the Show Updates check box on the top of the window.

3) Scroll down the list of installed programs and click Service Pack 3 or SP3. Click Remove. When prompted, click OK to confirm. Follow the guided prompts to complete the uninstallation. Click "Finish", then restart your computer when prompted.

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