I hope this thread is not closed as I have been experiencing the same issue - cannot hyperlink from Outlook 2007. However, I was using IE that was installed as part of Windows 7, I have never installed any other browser. There are numerous hits on the web for this problem and I have tried them all (I think )
Anyhow today I downloaded and installed Google Chrome, set Chrome as my default browser, lo and behold the hyperlinks in Outlook are working.
Then I set IE8 as my default browser and restarted Outlook and still the hyperlinks worked so I uninstalled Chrome. Alas, when I restarted Outlook the hyperlinks no longer worked.
So I now have Chrome installed but with IE8 as my default browser.
I have W7 64bit and Office 2007 all patched up to date. Not everyone can be wrong MS should sit up and listen.