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help with my lap
Check your BIOS settings. Set the CD/DVD reader as the first 'boot device', this means that the computer will try to start from the CD before attempting to lead the OS from the hard drive.
If you need detailed instructions on reinstalling, you can check out for example http://www.windowsreinstall.com/windows2000/installoldhdd/index.htm (This link is for windows 2000, otherwise choose the OS you want on http://www.windowsreinstall.com/)