In case you are looking for how to get the harddisk serial no: You can do this with Win API GetVolumeInformation.
http://msdn.microsoft.com/en-us/library/windows/desktop/aa364993(v=vs.85).aspx[
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BOOL WINAPI GetVolumeInformation(
_In_opt_ LPCTSTR lpRootPathName,
_Out_opt_ LPTSTR lpVolumeNameBuffer,
_In_ DWORD nVolumeNameSize,
_Out_opt_ LPDWORD lpVolumeSerialNumber,
_Out_opt_ LPDWORD lpMaximumComponentLength,
_Out_opt_ LPDWORD lpFileSystemFlags,
_Out_opt_ LPTSTR lpFileSystemNameBuffer,
_In_ DWORD nFileSystemNameSize
);