At first it may seems it is very easy question and some body may be trying to give me advice to try Google, it may be so. But for me it is very hard I have try Google, Stack
The best way I found is:
Download the .dll from here
Add the .dll to your project
Add this code:
[DllImportAttribute("HardwareIDExtractorC.dll")]
public static extern String GetIDESerialNumber(byte DriveNumber);
Call the hard disk ID from where you need it:
GetIDESerialNumber(0).Replace(" ", string.Empty);
Note: Go to the properties of the dll in explorer and set Build Action to Embedded Resource.