...unless you're alluding to security exploits that manage to subvert that mechanism.
...unless you're alluding to security exploits that manage to subvert that mechanism.
On Windows, any programs sharing a desktop are within the same security boundary and are not protected from each other by design.
If you want apps to be blocked from touching each other, they need individual user accounts or equivalent. Operating systems for phones do this, but this kind of system hasn't been ported to a normal desktop.
But until running mostly apps becomes the norm in a desktop system beware that not having admin privileges doesn't not mean you can NOT: load programs at startup, read most of registry settings, passwords, read memory of/close programs of same sec level. A malware doesnt need admin rights to do evil.
Still I believe AV products are useless even for inexperienced users.