Microsoft Outlook Hangs

Hi
I am facing one different problem I had Windows 98 system With microsoft outlook is for my mails.
Recently I upgraded to windows 2000 now my microsoft outlook is hanging as soon as I open.
I formated the HDD/changed ram/changed HDD also but still I am getting this problem.I observed one thning that whenever I make word has an e-mail editor it gives problem.I did office update and OS update also but still I cant use my MS Outlook with word as an e-mail editor option.
Pls suggest me what I need to do I checked my pst file,which wont have any problem.