Introduction
The new Windows Vista operating system seems to have it all – streamlined interface, flashy graphics, more power, better organization, advanced mobility and networking capabilities – and a number of new security features. Microsoft's Windows Vista is billed as the most secure OS version yet, but it is important to know that some of the "new" security features aren't all that new. It's also worth noting that Windows Vista in and of itself is not a security solution; rather it is a more secure version of Microsoft Windows. If you plan to run Windows Vista in your business, you need to take extra steps to make it secure.

Security features
Many of the technologies that Microsoft has employed to bolster the security of Windows Vista are not new. In fact, most are derived from the groundwork originally laid by open source operating systems and numerous academic publications. The majority of these security technologies first appeared in Windows XP SP2, which, at the time of its release, was also billed as the most secure version of Windows. The difference is that the security technologies are now enabled by default in Windows Vista, whereas they were disabled by default in Windows XP.

Still, Windows Vista does include more security features than previous Windows operating systems, including:

• User access control — Previous versions of Windows made it possible for malicious programs to perform downloads and installations without the user's knowledge. In Windows Vista, every time a software installation is attempted, the user will be prompted to approve the installation. In some cases, the user will even be asked to provide a password.
• Built-in spyware protection — An XP version of Microsoft's anti-spyware tool was previously available for download, but an anti-spyware program called Windows Defender is now built into Vista.
• Improved firewall — Previous Windows firewalls controlled only incoming traffic, a serious shortcoming. With Vista, the user has the ability to configure the firewall to manage outgoing traffic as well – however, users are finding that this manual configuration can be difficult.
• Buffer overflow protection — Address space layout randomization arranges applications in memory to protect against buffer overflows. Buffer overflows are the reason for many software vulnerabilities and are the foundation of many exploits.
• Safer surfing — Together with Microsoft's release of Internet Explorer 7, Windows Vista makes Web use safer. For example, ActiveX is disabled by default in Windows Vista, which is something savvy surfers had to remember to do themselves in the past.
• Encryption — The Windows Vista Enterprise and Ultimate editions come equipped with BitLocker Drive Encryption, which can encrypt the entire hard drive, making it more difficult for a hacker to access the computer's data.

Shortcomings
Despite the security features discussed above, however, Windows Vista still lacks crucial security components, such as:

• Antivirus — Computers running Windows Vista but not running a separate antivirus program are vulnerable to attacks from viruses, worms, and Trojan horses. Windows Vista's security mechanisms may remove or prevent malware from installing, but it isn't guaranteed. Microsoft makes this very clear, stating, "In addition to using built-in Windows Vista features, you should help keep your computer healthy by using antivirus software."
• Fraud protection — Windows Vista is unequipped to handle fraud-based Internet attacks. The latest version of Internet Explorer, Microsoft's Web browser, does contain some anti-phishing features. But Vista itself does not provide website authentication, phishing filters, or any other anti-fraud features. A third-party anti-fraud solution will need to be deployed to protect against these threats.
• Firewall — In March 2007, Orlando Padilla, a member of the Symantec Security Response team, released a report that stated that Windows Vista's firewall can easily be subverted by hackers via the unlock function. It is recommended that a separate personal firewall be used, something that not only blocks outgoing traffic by default but automatically identifies suspicious outgoing programs.
• Anti-spyware — Preliminary research conducted by some security vendors has shown Windows Defender to have ineffective blocking capabilities, slow definition updates and weak anti-spyware protection. Until the Windows Defender program proves itself in practice, it's advisable to install separate anti-spyware software with a demonstrated track record.

Conclusion
Security-wise, Windows Vista is an improvement over past Windows versions. In the first three months of Windows Vista's Business release, there's been only one patch released for the operating system. However, as the new version of the world's most popular operating system, Windows Vista is sure to be the target of new attacks. It won't be long before hackers and virus writers begin to uncover more points of vulnerability and exploit them. In order to plug Windows Vista's security gaps, you need to employ a comprehensive security solution.

from Symantec