How to Clear Unnecessary Empty Data Blocks from System using CMD

In CMD (Command Prompt), the "defrag" command is used to defragment a hard drive. Defragmentation is the process of reorganizing the files on a hard drive so that they are stored in contiguous blocks. This can improve the performance of the hard drive by reducing the time it takes to read and write data.

The syntax for the "defrag" command is: defrag [volume] [/a] [/h] [/m] [/u] [/v]

Where "volume" is the drive letter or mount point of the volume you want to defragment, and the optional parameters are:

• /a: Analyze the volume and display a summary of the fragmentation levels
• /h: Run the defragmentation operation at a higher priority
• /m: Defragment multiple volumes simultaneously
• /u: Print the progress of the operation on the screen
• /v: Verbose output that displays detailed information about the defragmentation process

For example, to defragment the C drive and display progress on the screen, you can use the following command: defrag C:

This will defragment the C drive and display the progress of the operation on the screen. Note that defragmenting a hard drive can take a significant amount of time, depending on the size and fragmentation level of the drive.

Note that the "defrag" command is not available in newer versions of Windows, such as Windows 10, which uses a different defragmentation tool called "Optimize Drives".