Having a bootable Linux on flash drive is very handly tool for a web developer. When I was about to create one, my TDK 16GB flash drive becomes inaccessible in my Windows 7 file explorer. The Windows explorer detected it and shows "Removable drive (H:)". When I clicked the drive, it prompted me to insert a disk in Drive H: as if it were acting as a CD or DVD drive. I checked it on my "Device Manager" and found my flash drive registered as "USB Disk 30X USB Device". I tried some known fix: uninstalled/re-installed the drive's device driver, re-assigned new Drive letter and nothing worked.