cannot open file server resource manager snap-in

[Anushet Shotiratana]

I've promote new Windows2003 R2 x64 EE to my windows 2000 domain as
additional domain. When I try to open MMC snap-in for "File Server Resource
Manager", "File Server Management" or "DFS Management". It said "MMC Could
not create the span-in. The snap-in might not have been installed correctly"
with specific identified as follow

File Server Resource Manager
CLSID:FX:{f8abd46c-1297-4474-9cdf-831ebb245f49}

File Server Management
CLSID:FX:{f7da6f14-f244-401a-9259-f015a82057d3}

DFS Management
CLSID:FX:{671ee405-c969-4af9-a61b-65e96b3b9a10}

How can I solve this problem?

Thank you in advanced

Anushet S.