If you’ve tried the updates and checked your Trust Center settings without success, another area you might want to explore is the file association settings in your operating system. Sometimes, these settings get changed or corrupted, which can affect how links are opened from third-party applications like Outlook.
To check this on a Windows system, you can go to Control Panel -> Default Programs -> Set Associations. Here, ensure that HTTP and HTTPS protocols are associated with your preferred web browser. If they're not, or if there's something unusual in those settings, adjusting them so that links always open with your browser of choice could potentially resolve the issue.
Additionally, it’s worth considering the add-ins installed in your Outlook 2007. Occasionally, add-ins can interfere with how certain features operate. You can test this by running Outlook in Safe Mode (you can do this by holding down the Ctrl key while launching Outlook). If links open correctly while in Safe Mode, then it’s likely that one of the add-ins is causing the problem. You would then disable all add-ons and enable them one at a time to identify the culprit.
Lastly, if none of these solutions work and updating isn’t an option for you right now, another practical workaround could be copying and pasting links into your browser rather then clicking on them directly from within Outlook. While not ideal, it could be a temporary measure until you find a more permanent solution or decide to upgrade to a newer version of Office.
Navigating these feeble software issues can be tricky but sticking with what works for you is important too! Let us know if any of these steps clear up your problem or if there's anything else we might be able to help with.