How to safely and permanently delete file data under Windows system

Most people always think that if you delete files or data permanently under Windows, you can use the Shift+Delete key combination directly. This is certainly not! Imagine if you can delete it permanently, how can there be such a data recovery software and method on the Internet?
Now assume that you have a hard drive in your hand that you have to send to the manufacturer for repair. There are a lot of important confidential information in it. Don't think about Shift+Del to delete it, or think further, you can't directly format it. Everything is fine? Still not!
This article introduces you to a command line tool that can permanently and completely delete the data files on the hard disk:
sDelete
No matter what else, download to the computer, download, compress, get sdelete. EXE. The first run will prompt you to accept the agreement and confirm. After running, nothing happens? Because it is a command line tool, open a command prompt before you can use it to delete files. Support for command line tools has many advantages, small size, free, and flexible parameters for easy batch calling.
SDelete refers to the US Department of Defense's document deletion standard DOD 5220.22-M. Because the principle is more complicated, we simply explain its operation process, that is, “write all 0s, then write 1 and finally delete” in the file content area. In addition, SDelete also considered the case of compressed files and EFS.
SDelete is a command line utility with many options. Follow the appropriate steps to delete one or more files or directories, or to clean up free space on the logical disk. SDelete accepts wildcards as part of a directory or file specifier. Its usage is as follows:
sdelete [-p passes] [-s] [-q]
sdelete [-p passes] -z [drive letter]
Parameter description:

-p passes the specified number of times overwriting performed;

-s perform recursive subdirectory;

-q no error;

-zClean up free space.


OK, in order to understand it as an example:

1. d: sdelete.exe -p 3 -s test.txt
   
   Copy code This command uses sdelete 3 times to delete the test.txt file under d:. Look, is it very simple, as long as there will be some simple DOS command operations can be