Zero out disk windows

Note that SDelete securely deletes file data, but not file names located in free disk space. SDelete is a command line utility that takes a number of options.

SDelete accepts wild card characters as part of the directory or file specifier. Securely deleting a file that has no special attributes is relatively straight-forward: the secure delete program simply overwrites the file with the secure delete pattern. Compressed, encrypted and sparse are managed by NTFS in cluster blocks.

If a program writes to an existing portion of such a file NTFS allocates new space on the disk to store the new data and after the new data has been written, deallocates the clusters previously occupied by the file.

NTFS takes this conservative approach for reasons related to data integrity, and in the case of compressed and sparse files, in case a new allocation is larger than what exists the new compressed data is bigger than the old compressed data. Thus, overwriting such a file will not succeed in deleting the file's contents from the disk.

Using the defragmentation API, SDelete can determine precisely which clusters on a disk are occupied by data belonging to compressed, sparse and encrypted files. Once SDelete knows which clusters contain the file's data, it can open the disk for raw access and overwrite those clusters. Cleaning free space presents another challenge. The first is that it can, like it does for compressed, sparse and encrypted files, open the disk for raw access and overwrite the free space.

This approach suffers from a big problem: even if SDelete were coded to be fully capable of calculating the free space portions of NTFS and FAT drives something that's not trivial , it would run the risk of collision with active file operations taking place on the system. For example, say SDelete determines that a cluster is free, and just at that moment the file system driver FAT, NTFS decides to allocate the cluster for a file that another application is modifying.

The file system driver writes the new data to the cluster, and then SDelete comes along and overwrites the freshly written data: the file's new data is gone. The problem is even worse if the cluster is allocated for file system metadata since SDelete will corrupt the file system's on-disk structures. United States English. Ask a question. Quick access. Search related threads. Remove From My Forums. Asked by:. Archived Forums.

Windows 7 Installation, Setup, and Deployment. Sign in to vote. I want to do zero out my hard disk. Monday, March 3, AM. It depends in the target goal. To write zeros to a hard drive so as to erase all the data, you can format the drive in a special way using the format command from the Command Prompt.

Follow the instructions below:. You can change the drive letter and file system based on your need. Tips: Formatting a drive of any size may take a long time. The lager the drive is, the longer time it will take. Once the prompt returns, repeat the above steps for any other partitions on this physical hard drive.

You can skip this step if there is only one partition on the hard drive. As you see, the process of zero-filling a hard drive via Command Prompt is really complicated and time-consuming. Is there a simpler way? Step 2. Step 3. In the pop-up window, you will see four wiping methods. DoD