I would recommend using
SandboxIE with your browser. The technical is that it creates something similar to a virtual space where the sandboxed programs can only use copies of important system files, so nothing actually is changed on your computer. Think of Sandboxie as a condom, where anything that would normally get on your computer can't, unless you play dumb. Then when you are done, the sandbox is tied up and thrown away. No muss, no fuss.