Free USB Guard v1.42

Free USB Guard is a tool that will alert you if your USB thumb drive or external storage is still connected to your PC when you try to shut down.

This can be particularly useful if your USB is bootable and the BIOS of the machine is set to check removable storage at boot before it checks the systems' HDD. It can also help when you are working on somebody elses' computer that you do not forget your thumb drive.

The software will pop-up a warning message if your device is still connected when trying to shut down, and it will halt the shutting down process until you remove the device.

The software is technically freeware, but does have a small nag screen asking you to donate to the project at start-up.