Using T.I. 9.0.2289, I successfully create a full disc image onto a Acomdata external USB drive, but it checks with error. I went under my Device Properties in windows and checked my properties for the usb drive. It listed two choices : 1. Optimize for quick removal (this choice was already selected), and 2. Optimize for performance, which enables write caching in windows. Would this make a difference? Which choice should I leave the setting on? I changed it to choice #2 thinking that may help, created another image to the external hdd, and checked it, but it still showed error.