Ran into an interesting problem in WinXP sp2. Virtual drives (including networked, mapped drives) that run run consecutively to your hardware drives will prevent your computer from recognizing flash drives. Either moving the drive letters around or changing drive mappings will fix it. However, I had a client use a working Attache on another computer and bring it back to her office and her computer would not recognize the drive. Turns out the machine was attempting to use F: (her first network drive) for the drive regardless of having an open E: drive available for it's use. Booting up the computer with the device in place disabled the network mapping and then she was able to use the device. I had her change the drive letter in drive manager to E: and then everything started up perfectly and the USB device could be removed and replaced with no problem. My only guess was the other computer recognized the device as F: and wrote that to the Attache. Hope this helps anyone out.