JkDefrag 3.36 is a System Optimizer product from kessels.com, get 4 Stars SoftSea Rating, JkDefrag is a disk defragmenter and optimizer for Windows 2000/2003/XP/Vista/2008/X64. Completely automatic and very easy-to-use, fast, low overhead, with several optimization strategies, and can handle floppies, USB disks, memory sticks, and anything else that looks like a disk to Windows. Included are a Windows version, a commandline version (for scheduling by the task scheduler or for use from administrator scripts), a screensaver version, a DLL library (for use from programming languages), versions for Windows X64, and the complete sources.
Permissions
JkDefrag needs "full control" permissions to all files and disks that it must defragment/optimize. On a default Windows system the "administrator" userid has full permissions to all files and disks. Users can also run JkDefrag, but then it can only defragment/optimize the files and disks for which the user has "full control".
Note: On Vista right-click the JkDefrag software and select "run as administrator".
Stopping
All versions of JkDefrag can be stopped safely at any time, there is no risk of losing data or corrupting your disk. You can use all the usual ways to stop a Windows program, such as pressing ALT-F4, clicking the 'x' in the top-right corner, via the pull-down menu in the taskbar, or by killing the software via the task manager or another utility. The commandline software can be stopped the same way, plus by pressing CTRL-C, or BREAK. It may take a bit of time for the software to actually stop, JkDefrag will finish the current file in the background.
Logfile
JkDefrag writes all messages to a logfile called "JkDefrag.log", or "JkDefragCmd.log", or "JkDefragScreenSaver.log", depending on which version you are using. You can inspect the logfile if you want, it's a flat-text file. The logfile is automatically cleared when the software starts, it does not grow to infinity.
Tip: you can use environment variables in the name of the logfile, for example "-l %COMPUTERNAME%.log". The license of this windows utility software is Freeware, you can free download and free use this Windows Utility software.