A co-worker asked me to install WordPerfect 8 Suite on her computer (it's a PII with WIN98 first edition and MSOffice97, on peer-to-peer Ethernet network). After installing that, OUTLOOK will not open. First, it kept reading "Cannot Start Outlook", so I renamed and replaced the MAPI.dll file - which got rid of THAT message.
Now it gives me an Illegal Operation message, as follows: Invalid Page Fault at Module 00000:0000001 etc.

I have tried removing (uninstalling) the wordPerfect8 Suite, but that has not helped.
Is this a compatibility issue between Corel and MSOffice?
Any Ideas? Anyone?
Bueller?

Have you tried uninstalling and reinstalling Outlook? If not try this one. I have come up against this problem before, I had a computer with Outlook 98 running OK on it. I then installed MS Office 97, and Outlook failed to run completely, however after uninstalling and reinstalling, all was well.

Think it might have something to do with the order in which they are installed.

Yes. After I posted this question, I went back and tried uninstalling tried reinstalling Outlook (as directed, through the add/delete in control panel). This did not help.
Then I uninstalled outlook all together, reinstalled it. Didn't help either.
I'm presuming now that there is an incompatibility of Office and WordPerfect programs. My next step tomorrow morning will be to try running a conversion/migration conversion patch,
Wp8cnv97.exe found at
\\asadmin\sys\updates\wp8\ms-wp8
which should help translate from Office 97 to WordPerfect.
I'll let you know if it works...
If you have any more ideas, I'm all ears!

Try removing everything (Wordperfect, Office, Outlook), then install Wordperfect first, followed by Office and Outlook. Everything should work then. MS Office doesn't share dlls and system files fairly. If Office goes in first, when WP looks for a file it isn't where its supposed to be. Once WP is installed first, it has access to all the system files in theri correct locations.