Overwrite hard drive - how it works

In order to permanently and irretrievably remove data from a hard drive, you must overwrite the hard drive. This works easily and reliably with the free CCleaner.

Overwrite hard disk: what happens?

• Deleting data from your hard drive doesn't mean that it's gone. The storage space is only released for overwriting.
• The data that once occupied this free memory can be read out with simple tools.
• When overwriting, the hard disk space - either only the free or the entire - is overwritten.

Overwrite hard disk: single or multiple?

• Most tools, like the CCleaner, offer different options: single or multiple overwrites. You can overwrite your hard disk up to 35 times with the usual tools.
• The more times you overwrite the hard drive, the longer the process takes. The so-called Gutmann method, in which 35 different types of overwrites are carried out, can take several days for a large hard disk.
• In his study "Overwriting Hard Drive Data: The Great Wiping Controversy", forensics expert Craig Wright came to the conclusion that after overwriting the data once, the probability of being able to reconstruct something is practically zero.
• So you can easily overwrite your hard drive without hesitation. If you have a more secure feeling, you can also choose multiple overrides.

Overwrite the hard disk with the CCleaner

With the CCleaner you can overwrite the free memory of a hard disk or the entire hard disk. You cannot completely overwrite the drive on which your operating system is installed. For this you need a special tool, which we will explain in the next paragraph.

1. Download the free tool CCleaner and install it on your computer.
2. Start the program and click on "Tools" on the left.
3. Select "Hard Disk Wiper".
4. Select whether you want to overwrite only the free space or the entire hard disk.
5. Here you can select the method with which you want to overwrite your hard disk.
6. Now click on the hard disk to be overwritten and select "Delete".

Overwrite system drive

To overwrite the system drive, usually hard drive C, you have to use a tool that can be started from a USB stick, such as Darik's Boot and Nuke, DBAN for short. Please note that the tool irretrievably overwrites your hard disk and you can only use the computer again after reinstalling an operating system.

1. Download the free DBAN tool.
2. With UNetbootin you create a bootable stick with DBAN. Download and start the tool.
3. Select "Abblid" and choose the downloaded DBAN version. Now select the connected USB stick and click "OK".
4. Now restart the computer and switch to the boot menu. Here you select the USB stick.
5. Start DBAN with Enter. You can adjust the deletion settings in the "Options" area. We recommend using the preset method.
6. Now select the hard disk to be deleted under "Disks and Partitions" with the space bar.
7. Start the process with the F10 key.

In the next practical tip we will show you how to clean up your computer with the CCleaner.