Prevent file changes, disable auto run, even disallow connection of USB drives, with USB Write Protect
This free and light program will let you disable writing on any connected USB drive on your computer, and of course enable it again whenever you like.
Why would you like to disable writing? Perhaps to avoid damages to your files from friends or kids, or even yourself, when you are using programs you don’t trust enough. More than this, the program can disable autorun, so that applications included in a USB drive, perhaps malware, won’t run automatically the moment you connect a USB drive.
USB Write Protect can also lock USB ports, so that no one will be able to connect a USB drive on your computer for whatever use, to export or import files to your computer.
Note also that the program can protect its settings with a password. Just make sure you won’t forget this password, otherwise you may find yourself unable to use your USB drives. In this case follow the URL included in the program to get a password reset utility.