Defraggler

It differs from other defrag tools on the market, by enabling you to quickly and simply defrag the files you want to, without having to process the whole drive. You can defrag only if the computer is idle for a definable time, so Defraggler does not slow down the computer if you work on more important tasks. Defraggler also lets you defragment multiple drives on the same PC, using different schedules. Defraggler uses the Windows Task Scheduler to enable you to set it for future defragging. Simply tell it how often you want it to defrag a drive (once, daily, weekly or monthly). Then it will go ahead on its own, tirelessly defragging your computer whenever you need it to. You can defragment your main C: drive every night, and your external D: hard drive every week. It's up to you. Simply run it, select the file and defragment in seconds. No more struggling with the Windows defragmentation tool! An original portable version exists, but it is not easy to find: http://www.piriform.com/defraggler/download .