/y is not a correct switch for windows del. For windows del you would want to use del *.* /s /q to delete everything.
Del = delete
*.* = select all files
/s = delete from subdirectories also
/q = quiet mode (don't ask before deleting)
with older versions of dos you would have to pipe the Y in there but /q works with newer versions.
The old deltree command used the /y switch to not prompt so maybe that is what he was thinking of?
