My logical disk d: disappear!!!(OS Win2k).Anyone Can Help Me?

Today I compiled the Addfilter sample in DDK\src\storage\filters and
Used command"addfilter /device \HarddiskVolume2 /add diskperf.sys" to load
the diskperf.sys on logical disk d:.Before doing this I have shut down
diskperf with command "diskperf -n".
Before doing that,I can see a
FS:FileSystemunnamed)-\FileSystem\Fastfat on device:\HarddiskVolume2 with
the DeviceTree tool(available at OSR download).
After doing that and reseting computer,I found My logical disk d:
disappeared!!!
Using anthother tool--Filtman.exe(available at OSR download),I found the
upper filter driver diskperf.sys on device:\HarddiskVolume2.
With DeviceTree,I can't see neither
FS:FileSystemunnamed)-\FileSystem\Fastfat nor diskperf.sys on
device:\HarddiskVolume2 .

Before my experiment ,DeviceTree reported:
-------------DEV \Device\HarddiskVolume3
|____[FT] File Systemunnamed) -\Filesystem\Fastfat

-------------DEV \Device\HarddiskVolume2
|____[FT] File Systemunnamed) -\Filesystem\Fastfat

-------------DEV \Device\HarddiskVolume1
|____[FT] File Systemunnamed) -\Filesystem\Ntfs

After my experiment done,DeviceTree reported:
-------------DEV \Device\HarddiskVolume3
|____[FT] File Systemunnamed) -\Filesystem\Fastfat

-------------DEV \Device\HarddiskVolume2

-------------DEV \Device\HarddiskVolume1
|____[FT] File Systemunnamed) -\Filesystem\Ntfs

What's wrong with my disk?How to add a disk filter correctly and
safely?Can I get my disk d: back?
Anyone can help me? Thanks a lot!