The idea is the browser does not to have read and write access out side it's folder area and thus it means it cannot read and write to other files and folders. Well in old days windows like windows 95 and windows 98 programs/applications and browsers like internet explore had full access and ran in administrator mode. Windows vista and windows 7 started sandboxing and not running in administrator mode. In theory sandboxing sounds great!! But in real world many malware are clever and can bypass the sandboxing. So the question is if user does not install a programs/applications or click yes for setting change what is going on. Why is the malware bypassing the sandboxing? Allowing read or write access. 1 a flaw in the way the sandboxing works? 2 a flaw in OS that has so many security holes that they are always bringing out patches for many vulnerable. 3 The way the OS is built that leads to lack of security and NOT much can be done but built new OS from ground up!! But all software and hardware will not work!!Why? Because of support of old hardware and old software. So it sorta of like how do we do this when people want support for old hardware and old software. 4 Java or flash? Do away with Java or flash and we will not have many of the problems. 5. The way the internet is? The internet needs big make over? Only other way is to install virtual machine or emulator . So if the browser sandbox application or OS gets malware there is less likelihood. Like running windows 7 but surfing internet in mini Linux OS emulator using Linux browser. Does Java or flash really have to go? How bad is Java or flash? Why is adobe so bad? What can be done? Is it time for windows to make new OS from ground up? Or in perfect world yes? But probably will not happen for other 5 to 10 years if ever? But yes even some people say OS X is starting to get old and Apple should work on new OS to replace OS X. Note the GUI can still look the same but under the hood every thing is different. But the problem is none of the old hardware and old software will work.