I am running windows 7 and have a 500gb drive with two partitions. I have been unable to wipe the secondary partition using both free and paid for drive cleaning utilities. I t looks like its working as while it's running the number of bytes used on the disk is decreasing, but after the system restarts nothing on the drive has changed - everything is still there!
I tried googling "hard drive maker cleaning tool" but nothing came up. Who is the publisher of this particular piece of software?
He means the cleaning tool recommended by the manufacturer of your harddrive. First remove the secondary partition, then resize the primary partition to use the full drive, finally zero fill the drive for 3 cycles. Whoever gets the drive will need a clean room and serious skillz to find out what kind of pron you like.