一个免费的基于GNU General Public License的Windows磁盘整理和优化软件,支持Windows 2000/2003/XP/Vista/X64.
全自动并非常易于实用,并支持USB磁盘和存储卡的整理,它利用微软的标准磁盘整理API制作,整理磁盘彻底,对NTFS的兼容性好并且不损害数据.JkDefrag v3.14 (June 9, 2007) Changes:
- Bugfix for the "-u" commandline option. All the "-u" masks were accidentally
 also processed as "items".
- Files are now classed as a SpaceHog when their last access time is more than
 30 days ago.
- Deleted the "full" optimization ("-a 4"). For backward compatibility the
 program still accepts the option, but does exactly the same as for "-a 3".
- The screensaver will now not start if it detects that the computer is running
 on battery power.
- Deleted the code that disables the Windows display idle timer (screen saver) and
 system idle timer (power saver) in the commandline and screensaver versions.
For programmers:
- Deleted message 57 from the message array.
- Changed the meaning of the "Data->Phase" variable used by the ShowStatus()
 callback.
- The ShowStatus() callback is now executed once for every zone in the "-a 3"
 and "-a 7"..."-a 11" optimizations.

官网:http://www.kessels.com/JkDefrag/index.html

官方下载:
for Windows 2000/2003/XP/Vista:http://www.kessels.com/JkDefrag/JkDefrag-3.14.zip
for Windows X64:http://www.kessels.com/JkDefrag/JkDefrag64-3.14.zip