I am getting bad state files error when syncing with USB key. Why?
Your USB key loses recently written files when you pull it out without stopping it first. You must tell Windows to Stop the USB key before pulling it out, so that Windows can flush its disk cache to USB. Right-click Safely Remove Hardware icon in System Tray (icon with green arrow), select Safely Remove Hardware and proceed to Stop your USB device. You can also set USB drive into a mode where disk cache will not be used, so you can pull out any time without stopping (however this was reported to not always work): * Click “Safely Remove Hardware” USB icon in Taskbar. * Check “Display Device Components” in dialog that comes up. * Click the “USB Flash Disk Device”, the middle one in the 3-level tree. * Click Properties. * Select Policies tab. * Select “Optimize for Quick Removal” and click OK.