Parallels 6, Windows 7, mid-2011 iMac running Lion. A USB thumb drive I plug into my iMac will not show up in Windows 7 Explorer, but it is showing up in: 1. The USB device list in Parallels (and is checked). 2. Control Panel/System/Device Manager/Disck Drives. 2. Windows/Computer/Manage/Disk Management. When I reassign a drive letter, the device transiently appears in Windows Explorer then vanishes again. So, Windows can see it, but I can't access the files on it to launch the security software and enter my UN/PW to get at my work. Any thoughts? Thanks.