This is a very important part of desktop or laptop computer diagnostics. One of the tools used to test the hard drive is the Windows Scan Disk. But the program lacks visual control and it does not show the actual hard drive surface. More than that, it displays no results even when a bad sector is found. Actually, as soon as a bad sector is found in the hard disk, it is better to transfer all data from that disk to another location and discard the disk.
Here is how you can test your hard drive with MHDD. First of all, you need to download an iso image from here and burn it on a CD. This is your bootable disk. Now, the actual test follows. First, we place the MHDD CD on the computer’s DVD drive and start the computer. Just after putting the power on, we press a key to go to the computer’s Boot Menu. This key is different for different computers and laptops. On my Dell, it is F12. On doing that, you should see a screen such as this.

 

You have to choose “Onboard or USB CDROM Drive”. Then choose “Start Computer without SCSI Support”.

Here is the screen where all available drives are listed.

In this case, the hard drive is listed with number 10.
Now, this part is important. You have to type the number 10 and hit “Enter”.

It will display a screen like this.

Now we type "Scan".

It will show a screen like this.
 
 

Here, you don't need to be changed anything. Just hit the F4 key.

It will start the test. On the right hand side, you will see the actual hard drive surface. On the left hand side, is program’s reporting field.
If there is a non readable block, it will display a message like this.

And it will update the report by showing a number in UNC.