May I respectfully suggest that as a newcomer to this forum you should take some time (as on any other) to read (or search) the existing material before issuing a barrage of questions ?

I just saw three in a row posted by you (this one, plus those on pdf readers and scroll mice), for which discussions and information already exist here. So do not be surprised or miffed if no one takes the time to duplicate these answers for you : as a friend of mine is fond of saying, "forums are not a write-only media"...