Java Defrag is a simple HDD defragmentation program, can pack the files of a directory together on the disk.

On an elevated command prompt (Windows Vista/7 UAC) or as administrator (Windows XP) execute:
java -Xmx128M -jar JavaDefragWin-0.1.jar

Controls:
1. F5 Select a disk and scan its contents
2. Left click on the drive map to filter files having that cluster range
3. Right click to clear cluster selection
4. Select a file from list to show its location on the disk
5. Middle click to toggle between fixed image display (e.g. paint the drive map into the current size) fixed cluster block size (paint the drive map using fixed cluster block size, use scrollbars to scroll down).
6. CTRL+Mouse Wheel: Increase the visual cell size of the drive map. (In fixed mode, this increments the number of clusters per block).
7. Use the star * and ? for filter on file name or path name.

Features :
1. No file move is implemented yet!
2. Directly scan NTFS and FAT32 drives for files (much faster than a recursive scan)
3. Display the drive allocation map and the location of fragmented files
4. Find files based on cluster range

The license of this software is Free, you can free download and free use this disk management software.