Since Microsoft is adding the SmartScreen feature, the company is removing the previous Security Warning alerts that appeared when you first opened a downloaded program (the old alert would show the verification status of the program publisher and warn you about running programs downloaded from the Internet).
This is a welcome change, as it cuts down on the number of alerts you have to click through--with Windows 8, you'll see an alert only when something's amiss.
Faster, More Secure Startup
Starting with Windows 8, Microsoft will begin to promote a new type of boot method, UEFI (Unified Extensible Firmware Interface), which improves upon and replaces the archaic BIOS boot system that most PCs have been using for decades. I won't get into the technical details here, but UEFI offers better security, faster startup times, and a number of other benefits.
Thanks to this new boot method (and other system enhancements), your PC will start up more quickly--in as little as 8 seconds, from the time you press the power button to when Windows fully loads to the desktop. But you're sure to appreciate the less noticeable improvements too. The Secure Boot feature of UEFI will prevent advanced malware (such as bootkits and rootkits) from causing damage, and it will stop other boot loader attacks (such as malware that loads unauthorized operating systems) as well.
Though Windows 8 will work on PCs with the old BIOS boot system, Microsoft will require new PCs that carry the Windows 8 Certification to use the UEFI boot system with the Secure Boot feature enabled by default. This Secure Boot requirement is causing some concern within the PC industry and among power users, as it could complicate the process of using Linux distributions or dual-booting multiple operating systems. However, Microsoft has promised to keep boot control in users' hands, and the company requires system makers participating in Windows 8 Certification to offer a way for users to disable the Secure Boot feature on PCs (but not on tablets).
Two New Password Types
Windows 8 introduces two new password types that you can use when logging in to your Windows account: a four-digit PIN and a "picture password."
For the picture password, you choose a photo or image and draw three gestures (a combination of circles, straight lines, or taps/clicks) in different places to create your "password."