Tools>Internet Options>General>Settings gives you some options, but not a refresh every 30s.
I'm not aware of a Registry key that sets the refresh interval. That doesn't mean there isn't one, by any means.
That being said, there's any number of freeware/shareware/proprietary add-ons for IE that let you auto-refresh, like:
http://www.clickgarden.com/about/userfaq.htmlhttp://www.davecentral.com/projects/ifocus/http://www.blackspiderwebware.com/webtaran.htmlhttp://www.webattack.com/get/bonusbar.shtmlI have not personally tried these. Some are freeware, some are not. If you really need this functionality, check 'em out and make your own choice.
HTH
Jon
A little knowledge is dangerous - none is absolutely terrifying!!!