If you want to do it through your own code, use a FileStream to read the files into memory and another to write them to the same file. FileStreams read the raw bytes of the files. You'll want to put some sort of delimiter between the files so you can separate them later. To add your delimiter to the file, create a string and then use System.Text.Encoding.Ascii.GetBytes(YourStringVariable). That will give you a byte array with which to write with the filestream's write method. Hope that wasn't too confusing! Ray PS: If you want to compress your files, there are lots of examples for compressing files in .NET, just search google for "compression vb.net"