How to clear history on IE 6.0 when clos

We are a public library with Internet access. I have just upgraded the PCs (OS–NT & W2000) to IE 6.0, but have found a problem with the history. The PCs are locked down & have no access to Internet Options. I have the history set to 0 but the dropdown still has listings of previous patrons. Need to find a way to clear this out. Thanks