I regret that I've not got a clue about the error code but I hope I can get your emails to print out in a larger font.
As you're probably aware, you can view your emails with larger text simply by going to View > Text size and selecting 'Larger' or 'Largest'. However, as you seem to have found out, the mail still prints out at the ordinary size. The way to get the mail to print out larger is as follows:
Close Outlook Express.
Open Internet Explorer.
Go to View > Text size.
Select 'Larger' or 'Largest'.
Close Internet Explorer (Optional).
Open Outlook Express.
You mails will now both display and print in the larger format.
Chris