Thanks for your reply. I would expect my suggestion to work with ANY word-processing program (such as Open Office's Write). It should also work with any DTP program, such as Microsoft Publisher.
Alternatively, download and install the best image viewing program ever (which is also useful for image manipulation and deserves a place on everyone's PC):
http://www.irfanview.com/
Open your image in Irfanview. Go to File>Print
Under 'Print Size' click 'Custom'.
Adjust the dimensions (and, if required, the margins) to your requirements.
Click 'Printer setup' to ensure that you're using the correct settings for your type of paper. Click 'OK' twice.
Chris