microsoft office - Using Outlook XP and Outlook 2007/2010 side by side on the same PC

I think there are a few questions around whether Office 2000/XP vs. Office 2007/2010 can be installed side by side on the same Windows (XP).

My case currently uses Outlook/Office XP and I am investigating if it would be possible to additionally install Outlook/Office 2010 on the same machine and then (for a short period) use Outlook 2010 alongside Outlook XP.

Would there be any specific complications using two versions of Outlook on the same machine? (Emails are retrieved via IMAP, no Exchange or pop3 here, so I do not expect any problems on the email protocol side.)

Answer

This Microsoft article discusses this same issue:
Information about using 2007 Office suites and programs on a computer that is running another version of Office.

In general, Office 2007 can coexist with earlier versions, but Oulook apparently cannot :

Multiple versions of Outlook

Microsoft Office Outlook 2007 cannot coexist with any earlier version of Microsoft Outlook. When you install Outlook 2007, the Setup program removes Microsoft Office Outlook 2003, Microsoft Outlook 2002, and Microsoft Outlook 2000. The Setup program removes these versions of Outlook even if you click to select the Keep these programs check box in the Removing Previous Versions dialog box.