In Netscape Communicator, pull down the Edit menu at the upper left (top row), and select Preferences. Then highlight Advanced, check Enable Java, and click OK. Then pull down the Go menu, and select Back to re-try the Protein Explorer.

In Internet Explorer, pull down the Tools menu at the top of your window, select Internet Options, click the Security tab, select Internet (or Local Intranet if applicable), click Custom Level. Under Microsoft VM, Java permissions, click "High Safety". Click OK to save the new setting, and OK close the Internet Options dialog.