The vidc.rlec=ativdacc.drv entry in the [installable compressors] section of the SYSTEM.INI file can      cause problems when playing large RLE-compressed movies. Remove this entry from the SYSTEM.INI      file. For update drivers, contact ATI Technologies Inc..

     Operating and Performance Tips: Performance and the Smartdrive Disk Cache.
     If your computer uses the double buffering feature of MS-DOS 6, AVI files may play slowly on your      computer. If your CONFIG.SYS file contains command that starts SMARTDRV with the      DOUBLE_BUFFERING parameter, add the /L switch to the SMARTDrive command in your
     AUTOEXEC.BAT file.
     If adding the /L switch doesn't increase the playback speed enough, try removing the      DOUBLE_BUFFERING parameter altogether. Before you remove DOUBLE_BUFFERING parameter, consult      your Windows documentation or MS-DOS Help to determine whether your computer needs the      parameter to run correctly.