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FltRegisterFilter returns 2 "File not found"

Dim_RyDim_Ry Member Posts: 2


I have just created an empty miniFilter with Visual Studio 2019.
I have copied MyFsFilter.inf MyFsFilter.sys to a target machine and successfully registered it by the mean of OSR Driver Loader.

When i try to start it with OSR Driver Loader I will see in DebugView that DriverEntry invoked. But FltRegisterFilter fails with
Status 2 "File not found".

How can i find what is missing ?

DriverEntry (

NTSTATUS status;


              ("MyFsFilter!DriverEntry: try FltRegisterFilter\n") ); **/// OK I see this in DebugView**

status = FltRegisterFilter( DriverObject,
                            &gFilterHandle ); **/// not OK 2 file not found error**

//FLT_ASSERT( NT_SUCCESS( status ) );

if (NT_SUCCESS( status )) {

                    ("MyFsFilter!DriverEntry: try FltStartFiltering\n"));

    status = FltStartFiltering( gFilterHandle );

    if (!NT_SUCCESS( status )) {

        FltUnregisterFilter( gFilterHandle );

return status;


Dmitry Rybakov

PS the same issue with SC.exe. SC.exe successfully creates a registration but SC.exe fails to start that service.

I tried Sysinternal PROCMON.exe to monitor file access but it does not peek into driver internals.


  • rod_widdowsonrod_widdowson Member - All Emails Posts: 1,137

    The usual reason is that you haven't configured the registry correctly for filter manager. Procmon will show you that happening (filter on the registry key)

  • Dim_RyDim_Ry Member Posts: 2

    @rod_widdowson said:
    The usual reason is that you haven't configured the registry correctly for filter manager. Procmon will show you that happening (filter on the registry key)

    Thank you for support,
    I have correctly installed minifilter using .inf file and started it successfully.

    The point was in [DefaultInstall] section. New version of Visual Studio reqiures architecture decoration. But after i deleted arch. decoration and installed .inf the service started.

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