Scheduled Defragmentation

To set scheduled defragmentation up use Windows Task Scheduler:

:: defragment Firefox cache
udefrag "%APPDATA%\Mozilla*"
:: defragment Google Earth cache
udefrag "%APPDATA%\Google\GoogleEarth*"
:: defragment small files on all non-removable disks
cmd.exe /C "set UD_SIZELIMIT=100MB && udefrag --wait --all-fixed"

Visit UltraDefrag Wiki for more information.