With 8GB flash drives available for under $20 and 32GB drives edging into the mainstream, there are a surprising number of uses for USB sticks. Vista has built-in software to convert your USB key into an actual key, such that your PC won’t boot without having it inserted. A USB key can be loaded up with much more powerful software, such as antivirus and file recovery apps, but a USB stick can be a lifesaving troubleshooting tool or an entire portable OS.”]
Source: https://gizmodo.com/dealzmodo-hack-make-your-old-usb-stick-into-a-digital-5101651