Java 1.1 already works on Internet Explorer 4.0 or higher.
You'll only need to change the security settings if you want to load and save Qfolios to disk. An applet doesn't have access to your harddisk, unless you give your permission. This is how you change your MS Internet Explorer security settings, so you can save your Qfolios.
By setting these security settings, you grant access to your harddisk not only to Q 1.0, but also to all other applets running on the server. Remember this when running other applets.