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Back up your hard drive. Determine which method of restoration is provided by the manufacturer. Insert the operating system disk into your CD/DVD drive. Wait for the CD to proceed automatically. Wait for the installation to complete.
Reformatting your laptop will cause you to lose all of your information so it is recommended that you back up your hard drive on an external hard drive, CDs, or DVDs if you wish to keep it. If you received a set of installation CDs with your machine, then use this. If you did not, your computer may have a restore partition set up, which means you will need to employ a different method. It normally auto-runs and will open to a menu, or options page. Select the option for installing a fresh copy of the operating system. If the CD doesn't run by itself, double click on "My Computer," and then right click on the drive with the OS disk. Click "Auto-Run." If you are away from the computer for awhile, it will pause at the next point, awaiting any required input from you. Follow the prompts, be patient and avoid the temptation to intervene. This process may take a few minutes. If you are reformatting your laptop hard drive, you will accept the default offerings/settings that the installation disc is asking for. When the operating system installation is complete, a completely fresh desktop will appear.