windows 7 rc is quite unstable for external devices. If I transfer data to my memory card, then somehow connection is not stable, then the explorer freezes. I plug out my usb card reader and then then whole system freezes. Tried ctrl alt del and it show this dialog, Failure to display security and shut down options. restart and freezes after showing desktop. Have to go safe mode, select scan disk of c drive, restart then can work.... -.- yoz...