VIN numbers are in the Code39 barcode format. So you really just need hardware capable of scanning a barcode. A cheap USB barcode scanner is about 20USD.
Then in VS, you just create a simple form with a text box. When the text box has focus, scanning a bar code will result in the text represented by that bar code (in your case a VIN) to appear in the text box just as if you had typed it in.
Also, if you want to go the other direction and generate bar codes in Code39, MSDN has a nice sample in C# here.