UltraDefrag是强大的开源磁盘碎片整理软件，适用于NT内核的Windows。目前还不支持NT 4.0。UltraDefrag磁盘碎片整理软件使用内核模式驱动程序，因此它的引擎是非常快，很简约；没有皮肤、没有本地化设置、没有动画.。它很小却很强大！它可以运行在Windows 2000，Windows XP 以及Windows Server 2003之上。

UltraDefrag(磁盘碎片整理软件)4.4.0 更新日志:

   UltraDefrag RC2:
    - history of typed commands added to the boot time interactive mode;
      navigation is possible by arrow keys, 'history' command can be used
      to list all typed commands
    - call, man and type commands added to the boot time shell
    - echo, exit, pause and set commands of the boot time shell improved
    - clearing of the failed boot flag added for reboot and shutdown at boot time
    - pending boot-off boot time script command support added,
      this removes the limitation of boot-on/off not working before reboot/shutdown
    - interactive mode at boot time now displays help split into pages
    - escape key handling added to break the boot time script execution
    - boot time commands parsing was rewritten to increase
      reliability and flexibility of the boot time shell
    - corrected cluttered progress display if console output was redirected
    - optimized timeout for waiting for a keyboard event in boot time interface
    - the following translations were updated:

      UltraDefrag Portuguese, Chinese (Traditional)

    - FAT formatted volumes are displayed in GUI now as FAT12/FAT16/FAT32
      instead of less informative FAT/FAT32
    - winx_heap_alloc replaced by winx_heap_alloc_ex to allow specifying flags
    - winx_heap_alloc_zero added to allow allocating memory initialized with zero
    - winx_ftw, winx_scan_disk, winx_fsize, winx_kb_read, winx_xtime,
      winx_prompt_ex, winx_get_file_contents, winx_release_file_contents,
      winx_wcsistr, winx_print_array_of_strings, winx_get_volume_information,
      calls were added to zenwinx library
    - winx_fbopen call added to zenwinx library for buffered file i/o support
    - obsolete winx_get_volume_size and winx_get_filesystem_name calls
      were removed from zenwinx library; use more common
      winx_get_volume_information instead
    - one little bug in winx_kbhit, winx_breakhit functions was fixed
    - udefrag_get_vollist and udefrag_release_vollist calls were added
      to udefrag library; an obsolete udefrag_get_avail_volumes was removed
    UltraDefrag RC1:
    - partial defragmentation was added to decrease number of fragments
      even when there is no free space on disk to hold all fragments of the file together
    - volume optimization algorithm was improved to prevent useless
      additional optimization passes
    - one little bug preventing optimization from being stopped was fixed
      in driver
    - volume optimization algorithm was improved to prevent skipping
      heavily fragmented parts of the processed volume
    - progress is now added to the GUI window caption,
      so it is displayed in the tool-tip of the task-bar icon
    - cryptic single character progress label was replaced
      by the localized operation names
    - file system type detection was rewritten to be more reliable
      and detect UDF-formatted volumes properly
    - fixed a problem where the case of the names of the help pages
      launched from the configuration dialog did not match
    - fixed a problem, where .lua files would get executed instead of edited,
      if "Lua for Windows" was installed
    - 10 seconds delay is skipped on boot time scan, if only one keyboard is present
    - added language selector to the GUI package
    - Hindi translation was added
    - the following translations were updated:

      Croatian, Danish, Dutch, French, Greek, Polish, Russian, Serbian,
      Swedish, Turkish