Understanding Well-Known Security Principals, Part 2

Restricted Code
Windows adds the Restricted Code well-known security principal to a user's access token when you run RunAs with the Run this program with restricted access option in Windows 2003 or the Protect my computer and data from unauthorized program activity option in XP. RunAs offers high-privilege accounts (e.g., administrators) a convenient way to switch to the security context of a least-privileged user when executing a program, thus limiting the exposure to malware inherent in their high-privilege security context. For more information about RunAs, see "Learn to Be Least," October 2005, InstantDoc ID 47622.

When the user's access token has the Restricted Code well-known security principal, Windows eliminates all rights held by the user except for Bypass Traverse Checking, prevents the application from accessing the user's profile, and allows only Read access to the HKEY_LOCAL_ MACHINE and HKEY_CURRENT_ USER registry hives. . . .