Earlier quoted context omitted.
Yes, it is common on Windows. When you are on their website to install Flash, there is a tick box you need to untick to avoid installing McAfee Anti-Virus with it. It is basically like the Ask toolbar bundled with Java. If you are not paying attention - which most people don't - you'll be installing unwanted software, because so much relies on basically crappy software (Flash and Java). Actually, that makes them crap…
As a developer, I kind of take offense to the allegations of Java (and Flash as well, I suppose, it's supposed to be pretty good) being "crappy software". The JVM is actually a rather awesome piece of software which offers good performance and good garbage collection. And interesting new languages have been created and flourished on top of the JVM. (Scala, Clojure) Please know the difference between bad/customer unfr…
That's the problem - the 'bad' installer/update makes good software into 'bad' software