Why do you need a proxy for exam registrations?
If you're trying to speed up access to a slow site, an open proxy will rarely make it faster. The only exception is if the proxy has a cached version of the site. But on sites where you need to submit information, and I suspect you need to on a exam registration site, a cached version won't do any good.
Ohh and a proxy should work regardless of browser, so there is no compatibility issues (unless you use some ancient browser).