How do I get the internal serial number of a USB-Stick or USB-HardDrive in C#?
I had problems with the solution offered by Yuval Adam as every USB stick I tried return blank on windows 7.
I solved this by just looking at the property PNPDeviceId on the current object.
E.g.
currentObject["PNPDeviceID"].ToString();
Not sure how valid this is but it worked for me on the 3 USB Sticks I tried