Can / Why Change Hard Drive Serial Number

Our anti-piracy software identifies people according to their hard drive. I believe this is a permanent feature and will not change unless the user changes their primary physical drive - correct me if I'm wrong? We are using WMI

python module to get custom hard disk serial number.

For our 2 test computers, the hard drive serial number has changed. But we haven't changed our hard drive at all.

What could be causing this problem? Is our code that identifies a series that is not universal across all Windows operating systems? I noticed that the post mentions that you can get the wrong serial number if the standard custom process gets the serial number. But in our case, the error also occurred at the administrator.

Some important information:

• Both of these test nodes are using Windows 8 Professional
• One computer is a Toshiba laptop.
• Another computer - Acer Iconia tablet
• The tablet was recently upgraded from Windows 8 to Windows 8.1 and I noticed that the serial number was changed after this update
• There is an admin user on the laptop who ran into a problem. The tablet has a standard user who ran into a problem.

Also is there the serial number of the hard drive the MAC address of the hardware device or something else?

Code for getting the serial number of the hard drive:

c = wmi.WMI()
for item in c.Win32_PhysicalMedia():
    if "PHYSICALDRIVE" in str(item.Tag).upper():
        serialNo = item.SerialNumber
        break

      

        
        
        
      

    

Edit: A short script that fetches the serial number of the user's hard drive as a normal process and as a promoted / admin process.

Note: For me, it outputs exactly the same serial number regardless of user or administrator. Does this script do the same for you?

import os
import sys
import wmi
import win32com.shell.shell as shell
ASADMIN = 'asadmin'

def get_elevated_privleges():
    if sys.argv[-1] != ASADMIN:
        script = os.path.abspath(sys.argv[0])
        params = ' '.join([script] + sys.argv[1:] + [ASADMIN])
        shell.ShellExecuteEx(lpVerb='runas', lpFile=sys.executable, lpParameters=params)


def get_hard_drive_serial():
    c = wmi.WMI()
    for item in c.Win32_PhysicalMedia():
        if "PHYSICALDRIVE" in str(item.Tag).upper():
            return str(item.SerialNumber)

    return None


print "HD Serial as Regular User: " + get_hard_drive_serial()
get_elevated_privleges()
print "HD Serial as Admin User: " + get_hard_drive_serial()