Install Opera and/or FireFox. Install NoScript in FireFox.

Make sure (with shortcuts, etc.) that Opera/FireFox is easier to
start/find than Internet Explorer. Try to make Internet
Explorer unsusable, like directing it to a non-existing
proxy-server, etc.

Make Opera/FireFox the default browser.

The following makes use inconvenient, but the question was
about security:

Block JavaScript for all sites (e.g. set in Preferences in
Opera and using NoScript in FireFox).

Allow JavaScript for some common sites, e.g. YouTube and
Gmail. Test that it actually works.