I was using Office 2007 but upgraded to Office 2010 beta. Outlook 2010 simply 
disappeared after 3 days leaving me with a changed Outlook icon on my start 
page that wouldn't open Outlook. I uninstalled Office 2010 beta. I had never 
uninstalled Office 2007 so it was still there, but I ran repair anyway before 
using it. The programs I use in Office 2007 (Excel and Word) opened but 
Outlook 2007 did not. I got two error message. The first says: 
"The mail profile "Outlook" was created with a newer version of Outlook and 
might contain information that is not compatible with your current version of 
Outlook. If you experience problem you can create and new profile... In 
windows control panel open Mail and create a new profile." 
I went to control panel but there is nothing labelled Mail in control panel.
The second error message says "Cannot open default email folders. An error 
has occurred. MAPI was unable to load the information service mspst.dll. Be 
sure the service is correctly installed and configured."
I have been able to use Windows Mail by setting it as my default email 
reader but keep getting the same error messages when I try to run Outlook 
2007.

Betas are never upgrades. Their installation and removal have never been 
tested. Accordingly, you would install a beta only on a test partition which 
you did not intend to use again for production purposes.
Anytime you change an Outlook version you must create a new Outlook profile. 
That's what the error message is telling you.
http://support.microsoft.com/default.aspx?scid=kb;en-us;829918&Product=out2003
-- 
Russ Valentine
"philtremiso" <philtremiso@discussions.microsoft.com> wrote in message 
news:9F13097D-E63D-419C-BC02-49B49CDF9B9D@microsoft.com...
>I was using Office 2007 but upgraded to Office 2010 beta. Outlook 2010 
>simply
> disappeared after 3 days leaving me with a changed Outlook icon on my 
> start
> page that wouldn't open Outlook. I uninstalled Office 2010 beta. I had 
> never
> uninstalled Office 2007 so it was still there, but I ran repair anyway 
> before
> using it. The programs I use in Office 2007 (Excel and Word) opened but
> Outlook 2007 did not. I got two error message. The first says:
> "The mail profile "Outlook" was created with a newer version of Outlook 
> and
> might contain information that is not compatible with your current version 
> of
> Outlook. If you experience problem you can create and new profile... In
> windows control panel open Mail and create a new profile."
> I went to control panel but there is nothing labelled Mail in control 
> panel.
> The second error message says "Cannot open default email folders. An error
> has occurred. MAPI was unable to load the information service mspst.dll. 
> Be
> sure the service is correctly installed and configured."
> I have been able to use Windows Mail by setting it as my default email
> reader but keep getting the same error messages when I try to run Outlook
> 2007.