How to Delete Everything on a Computer on Windows Vista

1. Save anything that you need on your hard drive. Once the format process completes, you will not be able to get any of the data off the drive without a data recovery service or software.
2. Insert your installation disk into your computer. Restart the computer.
3. Press a keyboard key when you see the message 'Press any key to boot from DVD.' This command boots your computer from the Vista disk instead of your hard drive, an essential step to being able to format the hard drive.
4. Press 'Next' once the installation screen loads. Click 'Install Now' to start up the Vista installation. You do not need to go through the complete installation process simply to format the drive, but you do need to start it to access the formatting tools.
5. Provide the product key located on the Vista DVD packaging. Click 'Next.' Check the license term agreement box. Click 'Next.'
6. Click 'Custom (Advanced)' instead of the upgrade option. Select the partitions that you wish to delete and choose 'Delete' for each one. You can create new partitions by clicking 'New' and assigning the partition size. Click 'Format' to format these partitions.