Take a look at this:

The only valid switches on the ZZ.EXE program are -ZZDUMP, -ZZLOAD,
and -ZZCHECK.  ZZDUMP creates the image on the drive, -ZZLOAD restores the
harddrive from the image WITHOUT VERIFYING IT FIRST!  Never use this
command.  If you want to restore, just use ZZTOP, option 2.  -ZZCHECK is the
command to check the image (ZZTOP option 1). ZZTOP will also work on Win NT
(Even though Dell doesn't use it on NT), but you CANNOT change the size of
the partition.

It came from the following website:
http://www.edgeworld.com/notebook/i7os.htm  Click on the link and then
search for ZZdump to read more.

Apparently the ZZ family of commands are part of a Dell restore program.

Art