Vopt (pronounce "vee-opt") is a Windows defragmentation utility sold by Golden Bow Sytems. It is one of the oldest defragmentation products, and has supported MS-DOS and all versions of Microsoft Windows. The convenience of quick processing time is offset by less optimal performance, but when used in conjunction with the built-in optimization of the Windows prefetch folder, system performance is maintained without major reorganization all the files on the drive.