Microsoft has unveiled a new Community Technology Preview of its forthcoming Windows Vista operating system.

The release includes enhancements to security, performance and the user interface, claimed Shanen Boettcher, a senior director with Microsoft's Windows Client Group, in a conference call with reporters.

The preview includes an updated version of Windows Defender, formerly known as Windows AntiSpyware, offering better detection and removal of spyware and malware and an improved user interface.

It will also run on a standard user account in Windows rather than requiring access in administrator mode.

Microsoft has also made available an updated version of its firewall software that now features bi-directional filtering. This enables the software to monitor the data that a system is receiving from the internet as well as data that it is trying to send, potentially blocking worms or spyware from connecting to their masters.

Internet Explorer will provide better notifications when a user visits a spoofed website set up to steal confidential information such as credit card numbers.

Microsoft had already revealed that the browser will use a list of known spoofing websites and turn the address bar red when a user visits such a site.

Boettcher said that Internet Explorer will also look for uncommon characters in the website's URL, based on the system's language settings. The software will, for example, issue a warning when an English user visits a website with a foreign character in the URL such as an 'ö'.

For enterprises, the software adds support for the IPSec standard for data encryption or authentication. Another feature courting enterprises enables IT administrators to control or block the use of USB memory keys through group policies.

"This has been a great concern in terms of data leakage, in files being copied on to these devices and then taken home or potentially lost," explained Boettcher.