I was thinking about using convert.exe without forcing the user to answer "y"... This might work:

1. Create a text file answer.txt
2. put just a "y" and a carriage return in it.
3. execute the line as follows:

convert.exe D: /FS:NTFS < answer.txt

I've found that you can often create an answer file that works so long as the command doesn't clear the keyboard buffer before asking for user input.

Brian