Some antivirus suites now block this because of exploits that rely on such links.
It has nothing to do with your account or system administrator. And let's clear off a misconception here. ALL versions of Windows must have a system administrator account. There is a fine example of stripping it out for a real locked down Windows but those that did that would know. So to write there is no system administrator you must be referring to a person and not the OS system administrator account.
Tell a bit more about your choice of security.
For some time now, if I try to follow a hyperlink in Excel or Word (2007), I get a message that says that it is forbidden on my computer and that I should contact the Syatem Administrator. I have no system administrator, as this is a home computer.
A Google search reveals that this is not a rare problem, and usually caused by uninstallng Google Chorome. I neer installed Google Chrome!
Several suggestions included setting IE as the default browser. That didn't help.