Do not delete the partitions on your hard drive, if you have important files on your hard drive and you will not be able to backup your files.
- Select the partition on which Windows is installed (see screenshot below).
- Click on the "Next" button.
- You will receive the following message (see screenshot below): If the partition you've chosen contains files from a previous Windows installation, these files and folders will be moved to a folder named Windows.old. You'll be able to access Windows.old, but you won't be able to use your previous version of Windows.
- Click on the "OK" button.
- The installation of Windows will begin.