Reinstalling won't help with configuration or data corruption issues.
Look in your account configuration where you stored your pst-file. Then
browse to that location and see if your pst-file is still there. If so, use
scanpst.exe to check it for errors;
See http://www.msoutlook.info/question/77
If it is not there, you somehow deleted it and you must restore it from
backup.

Signature
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more
http://www.msoutlook.info/
Real World Questions, Real World Answers
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> Today when I started to open my Microsoft outlook, I received massage
> informed me the outlook 2007 can't found my personal folders (Inbox, sent
[quoted text clipped - 7 lines]
> mean
> I lost my business.