Not sure what's wrong with running the built-in move command - it moves across file systems just fine on my desktop (Windows XP).
Moves files and renames files and directories.
To move one or more files:
MOVE [/Y | /-Y] [drive:][path]filename1[,...] destination
To rename a directory:
MOVE [/Y | /-Y] [drive:][path]dirname1 dirname2
[drive:][path]filename1 Specifies the location and name of the file
or files you want to move.
destination Specifies the new location of the file. Destination
can consist of a drive letter and colon, a
directory name, or a combination. If you are moving
only one file, you can also include a filename if
you want to rename the file when you move it.
[drive:][path]dirname1 Specifies the directory you want to rename.
dirname2 Specifies the new name of the directory.
/Y Suppresses prompting to confirm you want to
overwrite an existing destination file.
/-Y Causes prompting to confirm you want to overwrite
an existing destination file.
The switch /Y may be present in the COPYCMD environment variable.
This may be overridden with /-Y on the command line. Default is
to prompt on overwrites unless MOVE command is being executed from
within a batch script.