Longhorn will combine hardware locking with hardening of the OS to restrict memory access. Longhorn will feature User Account Protection, which means that by default local users aren't given full administrator access.
The first stage of enhancing security in Longhorn centres on the use of the Trusted Platform Module 1.2, a chip governed by the non-profit Trusted Computing Group and that is already being manufactured by Inifeon, National Semiconductor and Broadcom.Echert claims the solutions will be able to protect data in 99 percent of attacks. Longhorn will also feature system hardening, meaning that only certain parts of the memory can be written to, this should stop memory resident malware from causing disruption.
This will act as a vault for a user passwords and identity information. If a computer is stolen a thief would not only have to unlock the computer, but break into the chip to access any personal information.
User Account Protection will also protect the PC by locking down user rights, so hackers won't be able to get full control if a computer is infected. Read more at VNU Net