If Your Computer Has No Printer
Download and install PrimoPDF. PrimoPDF is a popular, free program that allows you to easily export your documents to PDF files. PrimoPDF installs itself to look like a printer on your computer. The presence of PrimoPDF will cause Jarte's printer related features to be enabled, including page numbering. After installing PrimoPDF set it as your "default" printer so Jarte can find it. You can set your default printer by going to Start > Control Panel > Printers.
You Have a Printer But Jarte Does Not Find It
First, ensure your printer is set as the "default" printer by going to Start > Control Panel > Printers.
Try downloading and installing the latest printer driver software for your printer brand and model. You can download the appropriate printer driver from the Support page of your printer manufacturer's web site. Close Jarte and restart it after the new printer driver has been installed.
Clear the Status Bar's "Printer Problem" Indicator
Your printer's driver software may have caused an error within Jarte when Jarte tried to communicate with it. This will cause Jarte to subsequently ignore the printer to prevent the error from reoccurring. In this case Jarte's status bar will display "Printer Problem". The solution that usually works for this situation is to download and install the latest printer driver software as described above. After the new printer driver has been installed click the "Printer Problem" indicator in Jarte's status bar while pressing the Shift key. That will clear Jarte's printer error flag and it will try to communicate with your printer again the next time you start Jarte. Close Jarte and restart it to see if it now properly recognizes your printer.