How to increase printing speed in c#.net

Your problem is that Crystal is printing in graphics mode, and a matrix printer in graphics mode is very slow. So you need to print as text. This means that you have to bypass the Windows driver and format your document by sending the appropiate escape sequences directly to the printer. One way to print directly to the printer is to open a file called "PRN" (use your favorite technique for writing to text files, such as a StreamWriter). Any characters that you write into that file will be output to the default printer port. Crystal Reports AFAIK does not know how to do this; you will have to produce the characters directly from your code, and apply formatting as needed by embedding escape code into the stream, which you will have to learn from the printer manual.