:/ Might I recommend some anti-virus software? 

I mean I don't know how the viruses got on there on the first place, but constantly downloading new browsers doesn't exactly seem like a great option. In fact, couldn't it be possible that a virus on your computer can spread to your other browsers? I'm no expert, so I don't know for sure. Just a thought.

But yeah, Avast is a pretty fantastic anti-virus program if you need one. 

Alternatively, if you're "running out of browsers", you can probably uninstall and re-download them.