Did you put

ChDir "\"

in a line following your

ChDrive "C:\" ?

If you did not the active directory  for C is not changed by the ChDrive
statement, that only changes the drive. Because of that the new dir is being
created in wherever in the C drve tree the active directory was. Then you
change to a place other than where you have created it.

An alternative would be to make your

MkDir "ABC"

MkDir "C:\ABC"