Getting an unhandled exception while trying to send string to printer. My Error: System.ComponentModel.Win32Exception: The handle is invalid

These are the two functions im using, this is working on my system but not on another system

public void print()     {         PrintDialog pd = new PrintDialog();         PrintDocument pdoc = new PrintDocument();         PrinterSettings ps = new PrinterSettings();         Font font = new Font("Courier New", 15);         ps.PrinterName = get_printer();         PaperSize psize = new PaperSize("Custom", 100, 200);         //ps.DefaultPageSettings.PaperSize = psize;         pd.Document = pdoc;         pd.Document.DefaultPageSettings.PaperSize = psize;  & ...