Basic troubleshooting – Outlook

Like with any other applications that are intensely used, Outlook can sometimes cause issues and return error messages.

No matter what the behaviour is, here are a few basic troubleshooting hints:

1. - here you can search for error messages, keywords and hotfixes

2. - this site contains a lot of tutorials and it can help with troubleshooting a certain issue, but also it can help you understand Microsoft products better (how they work, how to deploy them, upgrades etc.)

3. - as the title of the section says, this site presents “Top tips for Outlook”

4.       If you have an error or a certain feature is suddenly not working as expected, here is what you can try:

·         Install the last service pack for Outlook. Currently for Outlook 2003 the latest SP is SP3 , and for Outlook 2007, it's SP2 

·         Install the latest updates. Every two months or so, Microsoft releases what we call Cumulative Updates for Office. For Office 2007, the latest update is .

·         If you have the possibility, check if you are the only one in your environment (in your office, in your domain, in your organization etc.) that has this issue. This will help you determine if the issue is specific to your mailbox or machine, or if it's something that affects other users as well, and hence the cause needs to be analyzed from a wider perspective.

·         To further narrow down the cause, you can test on another computer and see if you have the same issue. If you don’t, then most likely there is something on your computer that is causing the issue (another application, corrupt profile etc.)

·         Try to check if you have the same problem in a clean(er) environment, which means first of all disabling all Outlook add-ins.

By add-ins, we refer to those COM add-ins that interact with Outlook and that you can see listed here:


For Outlook 2003:

Tools | Options | Other | Advanced Options | Add-in Manager and COM Add-ins



For Outlook 2007:

Tools | Trust Center | Add-ins


To make sure they are really disabled, you can go to the registry editor (go to Start | Run and type regedit), search for the following keys, then rename all the folders underneath these keys:






This will prevent the add-ins to load the next time you start Outlook. If after this your issue is solved, then you can start renaming back the add-ins one by one and see which one is the culprit. Add-ins are in fact one of the most common causes for errors and crashes in Outlook.

·         Recreate the Outlook profile. To do this, go to Control Panel, Mail | Show Profiles. Here you either have the possibility to add a new profile or to click on Properties | Email Accounts and then you have the Repair option for the profile.

·         If you have a calendar issue, you might want to check the following Knowledge Base article: (check as well the References section in this article)

·         Check if switching between Online mode and Cached mode in Outlook (Outlook 2003 and 2007) you still have the same problem.

·         If you encounter a performance or calendar issue, try to eliminate add-ins, synced devices (Windows Mobile, BlackBerry, iPhone etc.), additional mailboxes, shared calendars, SharePoint lists synchronized in Outlook, delegates on the mailbox having the issue.


The recommendations will not stop here, but we will break it down to specific issues, so stay tuned!

And if you have any suggestions or comments, we’ll be glad to hear from you!


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