Outlook MAPI32.DLL Error

Hi,
Please can you help at all?
I have installed Windows Vista on my PC and after installing my Office 2003
Pro I find that I can't use Office Outlook 2003 as it says the MAPI32.DLL
file is corrupt please reinstall. It says it's because ive installed MSN or
something.

I have tried reinstalling it and it hasn't fixed it. Is there a solution to
this problem?

Also if it can't be fixed I am a beta tester for the Office 2007 with my own
License Key. I downloaded and installed the beta on my laptop then deleted
the downloaded files. The office 2007 beta is still on my Laptop. If all
else fails with the problem I have I may uninstall Office 2007 Beta from my
Laptop and install it on my PC. The only problem I have here is I no longer
have the downloaded office 2007 files, I only have the installed files on my
Laptop. Is there any links that will allow me to download it again. As I
say I have a key so just need the files or somehow re-use the installed files
off my laptop.

Vista rocks! love it, just need to iron out these little problems.

Cheers

Lee