A. File Manager, or WINFILE.EXE is no longer supplied with NT and thus not available under Windows 2000.
If you upgraded a 4.0 machine to Windows 2000 then File Manager is not deleted and will still be available, also you may copy WINFILE.EXE from a 4.0 machine to Windows 2000.
Under Windows 2000 you may also use the File Management MMC snap-in.
I would say that by now you should be using Explorer and not File Manager anyway to take advantage of the advanced feature set provided by Explorer.