ZDNet has written an article about some of the new security features found in Microsoft Windows Vista.
And speaking of restrictions, Microsoft also plans to reduce the amount of kernel-level code in Vista, relocating a number of device drivers and virus scanners that currently write to the protected areas of the system registry. For example, all printer drivers write to the kernel, requiring a reboot. The downside is that if the printer driver ever misbehaves, it'll take down your entire system. Under the new Vista plan, printer drivers, antivirus scanners and other devices will install on the user level only -- not within the OS kernel. As a result, look for new Vista-compatible antivirus products to be released next autumn.