If you are using Outlook 2013 (or above), you can no longer upgrade just Outlook. You need to install the entire Office suite
Is it a good idea to upgrade Outlook only and use it with your older versions of Office? It depends... on the features you use and rely on and what your are willing to give up. The most noticeable problem is the editor is limited and missing features. You need to install Outlook and Word from the same suite to have the full editing capabilities of Word.
In Outlook 2007 and Outlook 2010, you'll have a limited version of Word available when only Outlook 2010 is installed, with some spelling and grammar features are missing. See Outlook 2010 Standalone and Features not available when only Outlook 2007 is installed for more information about those programs
In Outlook 2003, Word cannot be used as your email editor unless its installed from the Office 2003 suite, but even if you never use Word as your editor, there are other issues to consider before installing Outlook.
Tip: If you copy winword.exe from the old directory to the same directory as outlook.exe, you'll gain some of the spelling and grammar features back.
What you'll lose by upgrading only Outlook:
- Word as your email editor. In order to use Word as the editor, you need to use the same version of Word and Outlook. There is no hack you can use to make Outlook 2003 use older versions of Word as it's editor.
- Mail merge when initiated from Outlook's Contacts. You can still use mail merge if you begin it in Word and can use Outlook's Contacts in the merge. What do you lose by not starting the merge in Outlook? The ability to use Outlook's more powerful filters to create the mail merge dataset.
- Office envelope. This is the email header that's displayed in Word, Excel and other Office programs when you click the envelope button or choose File, Send to, Mail Recipient. You can still send documents as attachments.
- New Letter to Contact. You won't be able to select a Contact and choose Actions, New Letter to contact.
Reasons to Upgrade
If you can tolerate the losses, this is some of what you'll gain:
- New features, including the Reading pane and Search folders, that make reading and organizing your email a much better experience.
- Improved spam filter
- Better email security against viruses
- Cached Exchange mode.
- RPC over HTTP (if using Exchange 2003)
While you don't lose a lot of features and there are simple workarounds for mail merge, we don't recommend upgrading only Outlook, even if you never use Word as your email editor. Outlook and the other Office programs work much better together when all of the applications are at the same version level.
The following Outlook 2003 features are unavailable unless Word is your email editor.
- You lose the ability to right click on a signature and choose a different one.
- Select a different email account and the signature changes to the one assigned to the new account
Open Word and browse to the Tools, Letters and Mailings, Mail Merge menu and follow the wizard to create your merge.
You can use these methods to mimic the Office envelope and send worksheets or selections (without using objects):
Both samples by Ron de Bruin, Microsoft Excel MVP
Upgrading just Outlook means twice as much work when applying patches and service packs, as you need to apply patches for two (or more) versions. You many need to repair Outlook 2003 after installing patches for older Office applications.
There are reports that updates reinstall Outlook 2002 bits. This results in Office XP needing to reconfigure itself each time Outlook 2003 is active.
Detect and Repair may be more difficult and require media for each version of Office.