ChkDsk on Vista

I am using ChkDsk() exported function from system provoided fmifs.dll to
achieve chkdslk functionality from my application.

I am registring my callback to ChkDsk() function.

In XP, When I return FALSE from my callback, I am getting 'FmIfsFinished'
type of packet. But in Vista I am not getting this; instead am getting packet
type of "25" value.

'FmIfsFinished' is enum variable from FMIFS.H header file and Packet type
enum 25 value is not defined in FMIFS.H.

With this observation it is very evident that this header/DLL has changed
from XP to Vista.

It would be of great help if somebody help in finding updated header file
for vista ?

Thanks.