Don’t discard the security benefits of User Account Control (UAC). UAC is a Windows 7 in-built tool that protects your system but more important, UAC is a security feature that informs you when an action requires elevation of privileges. For more details about UAC go here and here.
UAC is a security feature of Windows 7 that informs you when the action that you want to take to undertake requires an elevation of privileges. It is a common practice, actually a bad practice to log in with a user account that has administrator privileges. For instance, a user account that is a member of the local administrators group is used as a normal user account in the day to day operations such as, Internet browsing! Administrative user accounts are intended for tasks related to administration and running your computer in this mode for ever presents a security risk because any program run by the user in this mode runs with the rights and privileges of an administrator.
The Runas command is a great command-line tool that gives you the capability to run applications using the credentials of another user but watch out as you may be compromising security of the Windows 7 system. For instance, with the Runas command you can allow a standard user on a Windows 7 system to run applications that require administrator privileges.