New Feature of Windows 7 security

Windows 7 is the latest public release version of Microsoft Windows, a series of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbooks, tablet PCs, and media center PCs.
Windows 7 has enjoyed approving adoption, yet many IT admins are now struggling with the platform's new security features.

User Account Control :-

User Account Control (UAC) is a technology and security infrastructure introduced with Microsoft's Windows Vista and Windows Server 2008 operating system. It prompts less frequently for low-risk administrative actions by default, but it allows admin to change the prompt sensitivity using a slider bar. It aims to develop the security of Microsoft Windows by restrictive application software to ordinary user rights until an administrator authorizes an increase. In this way, only applications trusted by the user may receive administrative rights, and malware should be kept from compromising the operating system.
Recommendation: Your domain environment should already be at the highest and most secure level. If it isn't, make it so. That way, users will be prompted to input their passwords to perform high-risk administrative actions. No matter what else, UAC should be enabled.

BitLocker:-

BitLocker Drive Encryption is a full disk encryption characteristic included with the Ultimate and Enterprise editions of Microsoft's Windows Vista and Windows 7 desktop operating systems, as well as the Windows Server 2008 and Windows Server 2008 R2 server platforms. In Windows 7, BitLocker Drive Encryption technology is extended from OS drives and fixed data drives to consist of removable storage devices such as portable hard drives and USB flash drives. This expansion is called BitLocker to Go.