If you are running outlook 2007/2010 you may run into an issue where you are Outlook crashes when printing, rendering you unable to print.
Thankfully, there is an easy fix, as the issue is with the OutlPrnt file under:
C:\Users\App Data\Roaming\Outlook in Win7
C:\Documents and Settings\Local Settings\Outlook in XP
Just rename this file OutlPrnt.old and run a repair of Office and reboot. Upon printing in Outlook, this should fix the issue. If NOT, change your default printer and print, then switch it back, and it will be working again (Although this fix may not be permanent)