Can someone help me with Outlook issue??

my uncle is using outlook express at his office for his main email. All of sudden his email is locking up, and taking up 100% of the cpu usage (as per task manager said). I plan on reinstalling outlook express but we need to save emails that he had already downloaded from the isp. Can anyone tell me a program that will retrive the email/ or which file to save in the outlook express folder.

Any help wud be appreciated.