Blancco Drive Eraser is able to store an erasure report on the hard disk drive's master boot record (if the feature was set on before the erasure). To remove the report, boot the computer with a Windows boot disk or Windows installation CD and enter the repair prompt mode. Run the following command: "fdisk /mbr". This command re-writes the boot sector and removes the Blancco report. Installing an operating system (Windows or Linux) will also remove the problem, as the MBR will be cleared during the installation.
Google for example "windows boot disk" for more information on how to create a boot disk and restore the boot sector.