This is an example of how you can print to PDF files from Microsoft ASP.NET running on IIS (Internet Information Server). The example is written in C# (C Sharp). However, the principle of the example can be translated directly to VB.NET.
The example web site you can find in the download below shows two different methods of creating PDF files. One example prints directly to a postscript file that is passed on to the gui.exe process from the Bullzip PDF Printer installation for conversion to PDF.
Another example show you how to send the print job to the Bullzip PDF Printer port and have that do the conversion.
The web site was built in Visual Studio 2010 and are using Microsoft.NET Framework 2.0.