No matter what I do I cannot get either of these local File URIs:

<a href="file://C:/Folder/">...</a>
<a href="file://C|/Folder/">...</a>
<a href="C:\">...</a>
...

...to work in IE7 (on Vista). I've tried putting the site in different zones (Local Intranet, Trusted Sites), turning on/off Protected Mode and fiddling with the security settings for the active zone. I've also tried many variations of the URI. But when I click the links, nothing happens. No errors either.

Well-formed file URIs to the local file system work in all other browsers I've tried, including IE6 and IE8. I've also gathered from what I've read on the web that this should work.

Also, the following JavaScript results in an access-denied error, regardless of zone/settings:

<a href="#" onclick="return window.open('C:\\Folder\\');">#</a>

Did this stop working in the latest IE7 and/or the latest Vista, or something? And if so, why is it working again in IE8 on Windows 7?

Is there a workaround of some kind?

(I don't know how to test with IE7 on anything other than Vista.)