Examples of various privileges include the ability to create a new user, install software, or change kernel functions.
Modern processor architectures have multiple CPU modes that allows the OS to run at different privilege levels.
When a task tries to use a resource, or execute a privileged instruction, the processor determines whether it has the permission (if not, a "protection fault" interrupt is generated).
In computer programming, exceptions related to privileged instruction violations may be caused when an array has been accessed out of bounds or an invalid pointer has been dereferenced when the invalid memory location referenced is a privileged location, such as one controlling device input/output.
This is particularly more likely to occur in programming languages such as C, which use pointer arithmetic or do not check array bounds automatically.
Unprivileged users usually cannot: On Windows NT-based systems, privileges are delegated in varying degrees.
An account (user) holds only the privileges granted to it, either directly or indirectly through group memberships.
Some administrative privileges (e.g. taking ownership of or restoring arbitrary files) are so powerful that if used with malicious intent they could allow the entire system to be compromised.
Whenever the user wants to perform administrative actions requiring any of the system privileges he/she will have to do this from an elevated process.
When launching an elevated process, the user is made aware that his/her administrative privileges are being asserted through a prompt requiring his/her consent.