Hi,
For VS 2003, please try to add reference to .net 1.1 dll. The default location is "C:\Program Files\Aspose\Aspose.BarCode\Bin\net1.1".
If you are using VS 2005, then .net 2 version of the dll should be referenced.
Best Regards,
Saqib Razzaq
Support Developer
Aspose Guangzhou Team