At this point, a full format and reinstall isn't a bad idea. And if you've had that many issues with being hacked, I'd highly suggest an authenticator. Though I do suggest authenticators to everyone. Extra security is never a bad thing.
Also, remember that keyloggers don't magically appear on your system. I usually suggest FireFox with the AdBlock Pro and NoScript plugins. Also, a good anti-virus (
Avira is free and pretty good, though the ads can be annoying) and anti-malware solution (
MalwareBytes). With that setup, if used properly, you can browse to your heart's content and hardly fear a keylogger.