You can plot a drawing to a file rather than to a plotter or printer. Because you can plot this file later without opening AutoCAD LT, you can send the file to a plotting service or use a spooler to plot the file.
The plotted file uses the current drawing name with a different file extension. Your plotter may specify a file extension automatically, or you can specify one when you plot. Otherwise, AutoCAD LT adds a .plt file extension.
If you have trouble plotting to a file, you may need to change some settings in Windows Control Panel.