outlook shut down

Outlook express shuts down at times when I hit the reply button. It says and error has occured and needs to close. I box comes up to report, I report. Since purchasing this new computer on February 1st, I have install MS Works, Print Shop 10 and HP Mulit-function office jet d145. This came with the standard home Windows XP edition and Corel. After installing MS Works, corel products won’t open.