Do not enable compatibility mode – this is not needed and will cause problems with any version of Outlook.
Outlook 2002, 2000, 98, and 97 are not supported on Vista. If you choose to install any of these applications you should expect errors and annoyances. The better known problems for Outlook 2000 are listed below but there may be others I'm not aware of. See Outlook on Vista (and Win7) for problems associated with the other versions.
These versions of Outlook are all long out of support and Microsoft will not release patches to fix any problems with these versions. Upgrading is highly recommended, or use the new Vista calendar and mail applications if you are unwilling or unable to upgrade.
With more extensive use, additional issues and workarounds may come to light. If you are using Outlook 2000 for email because you need the calendar, it's probably well worth your time to try the Mail and Calendar applications included with Vista. Windows Mail is more secure than Outlook 2000 and includes anti-spam filtering. The Calendar application supports many of the features found in Outlook 2007′s calendar, including calendar sharing and publishing. If you are using Outlook for Word's spell check, Windows Live Mail Desktop supports "spell check as you type".
If you want to keep using Outlook 2000, keep reading.
Internet Mail Only Mode wab.dll Error
Internet Mail Only (IMO) mode will fail due to the missing wab.dll (Windows Address Book). You can try copying the wab.dll to Vista and registering it. While this will end the error, the address book may not function correctly. For more information on this fix, see Hack the WAB.
Corporate / Workgroup Mode
Corporate/Workgroup mode seems to work fine, except the Startup dialog comes up each time you restart Outlook (click Next and work your way through the dialog).
After installing Office 2000:
Use Regedit and go to:
Change the default value for Calendar, Contacts, Mail, and News to "Microsoft Outlook".
In the HKEY_LOCAL_MACHINESOFTWAREClientsMailMicrosoft Outlook entry
add a Type Reg_SZ entry named "MSIComponentID" and give it a value of
Rob adds: "I had a user that wanted to use the "Send to" option for mail recipient. The fix for that:
From the start menu's search box (at the bottom of the menu) type "shell:sento". This should open a window showing the various sendto options. Place a shortcut to Outlook.exe in this folder and rename it to "Mail Recipient". If there is an original "Mail Recipient" already there then move it somewhere else… "
The shortcut is a good idea for anyone who uses the Send to mail command very much – it honors the default stationery, signature and editor options you set. Rob said they didn't need the switches – if it errors for you with just the outlook.exe in Send to (or to use with other versions), see Send To Revisited for the switches you need to use.
Other Versions of Outlook
Outlook on Vista (and Win7) original page. Covers Outlook 2003, 2002, 98, 97.