Now we come to the step where we remove any previous Windows installations and all existing partitions on the drive so that there can be no future conflicts regarding the Windows boot partition information. I recommend selecting, one at a time, and deleting, ALL existing partitions on the primary drive until no partitions remain and there is only unallocated space.
(Do not delete any partitions showing that are on the USB flash drive you are using to install windows from, if it shows up in the list of partition information. All others may be deleted unless you still have other drives connected.)
If you have not disconnected all secondary drives as was suggested at the beginning of the tutorial, then be very careful to not accidentally delete any partitions from those drives by mistake.
If you still have other drives connected other than the USB or optical drive being used to install from, and the target drive for the Windows installation, I highly recommend stopping now and starting over again from the beginning AFTER shutting down and disconnecting those drives.
If there ARE no other hard drives connected, then proceed with removing all of the existing partitions on the primary hard drive, until only unallocated space remains, and then click Next.