WHY CAN’T EMAIL INVOICES USING SIMPLY ACCOUNTING 2005 PRO?

I’m trying to email invoices using Simply Accounting 2005 Pro. I use Outlook Express 6 email and I have Windows XP. Error message is, “You have always printed your invoices. What do you want to do: EMAIL PRINT CANCEL.” I choose EMAIL. Error message is: “Cannot find Crystal Reports print engine. Download and install from Installation Disk.” I have done this. Still get same error message.