What The E said. Also, I completely fail to see how admin mode would disable the firewall or antivirus, or any other security measure. You have also failed to list anything admins need to run that users do not.
The sole purpose of user mode and UAC is to restrict the normal users from doing stupid things. Nothing more.
I didn't say how admin mode would disable the firewall or antivirus or any other security measure. I was saying for the event when running as admin 24/7, that you rely on two things for security. One is your firewall. Two is your virus scanner. Time and time again, virus scanners and firewalls do eventually crash. In an admin 24/7 environment that leaves you with no extra layer of security. This is why it's stupid to run as admin all of the time. This is simple. This is why it's smart for administrators to not run as admin 24/7.
It's more than that that you don't see about how handy standard user accounts are. What The E said does not negate the use of standard user accounts effectiveness. It is still inherently more secure to run your computer through a standard user account. It's not just for stupid users. It's great for damage control. And of course, yes, rootkits can run in standard user accounts, but it's still stupid to say "well i should go back to admin" which is an even less secure environment where you malware and rootkits can all run rampant as opposed to just the rootkit risk.
The E, social engineering is a different subject. And i disagree. Standard user accounts are still very effective.
An approval by approval basis for admin privileges lets you run the computer how you want to run it. Running as admin becomes the opposite if a virus gets through and doesn't get taken care of. In which case i liken an admin account to a retard with a shotgun. The retard says yes to everything (yes trojan please access the rest of the system as you want because admin accounts have no permission limitations, or at least not many), and only shoots what you tell it to shoot, but that you may not catch everything that needs to be shot (like that virus that got past you when that virus scanner crashed).
Running as standard user using UAC to temporarily grant whatever you needed admin privileges for lets the retard with the shotgun say yes to only the things you want yes to be said to, and of course still retaining the ability to tell it to shoot whatever you want it to shoot.
It's not about protecting you from yourself on the computer, telling you how to run it, or being paranoid which is being stereotyped lately. It gives you more control over your computer, it also really helps in making viruses have no lee way unless you give them that lee way on purpose (great if virus scanner crashes, viruses wont be able to do crap anyway). It also gives hackers who break into the system a lot less things to do (if firewall crashes). Aside from people running tight ships for their computers, relying on only a virus scanner and firewall is not a good idea (time and time again one or the other or both crash). So i don't like running as admin 24/7 and never will. I also don't need to worry about people hopping on my computer and installing crap i didn't want on there.
This is not hard to understand. Telling me it's about paranoia, the computer telling you how to run it, or even protecting yourself from the computer is not good reasons for why you shouldn't run as standard user. Everyone has thoughts of UAC being useless. I will point out again, that
UAC is only useful when running as standard user. When running as standard user UAC is not different than gksu or kdesu in linux.
It's a ****ing password prompt for god's sake. In a standard user account, this is a big upgrade over xp's runas window.

In the end, it's not a good idea to run as admin 24/7. Linux and unix have this as a basic foundation of their security. Since vista and the vista rerelease windows 7, people can finally replicate the same security in windows easily. You can do more with less programs in a more secure environment, have a lot less down time, efficiency will raise, mistakes wont matter so much, and it's much less volatile. You cannot tell me running as admin 24/7 is a good idea.
Run your computer the way you want, but telling me i'm offering bad advice when people can tell me nothing more to the contrary than "it's about protecting you from yourself", "telling you how to run the computer", and "it's paranoia". None of those responses tell me how it's bad advice. Those are called emotional responses. Just get your case over with by simply saying "hi i'm kyadck, i like to run as admin, that's my preference". Giving me emotional responses didn't get much done and only showed me that people didn't know what i was talking about.
Kyadck changes and twists what he says, he offers no more than preference, loads and loads of pissy emotion, and lies. Just say, "hey, i don't know what you're talking about". Kyadck either still doesn't understand me, or he does and proves it with twisting what i say and twisting what he says. I've talked about it enough without anybody understanding to know that the audience is stupid and kyadck is an obvious mischief maker who can only concert himself as a liar who's much less valuable than he knows (he just flames people and trolls).