Why does Apple suggest New User for problems?

[acme]

I'm noticing more and more that Apple tech people frequently reach for the "new user" solution to many problems.

I get that a User can become hosed, but it is suggested often, and a few times, was suggested right after doing a brand-new install of Lion!

Is OS X such weak sauce that the User ƒ can spoil so easily?

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[NaOH]

I don't get the sense that it's on the rise as a troubleshooting step, but that's just me. I do think it's a helpful measure for a number of reasons. For one, computers are modified in all manner of ways, whether that's software downloads from who knows where, multiple users sharing a user account, software installers that overstep the usual bounds (for example, Creative Suite), and people making changes when they don't really know the implications. On top of that, people in need of help are often flimsy with their explanations. They might say, "My computer suddenly does (or doesn't do) ________," but no context is provided.

Considering how difficult it can be to provide indirect support—whether forums like this, on the phone, etc.—a new user account is a fast, harmless way to determine if a problem is specific to a user or account or systemwide. And the answer is significant for the person who is helping because it can provide a big piece of information for how to find a solution.

Say you hurt your knee playing sports. You limp into the doctor's office and go to the exam room. What do they do? They take your blood pressure. Before they look at your issue, they check how your system is doing. A new user account is similar.

[acme]

those are some seriously good points, NaOH...especially the parts about installing software from who knows where, and doing things one doesn't know the ramifications of doing..


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[anthlover]

It is as close as you can come to doing a clean install for trouble shooting without actually doing so.

[dianeross]

Testing in a new User will quickly tell you if the problem is system wide or if it's your User's folder that contains the problem.

Once you know the source of the problem you can start looking for a solution.

[benwiggy]

OS X is structured with a clear divide between the user and the system. You will know that the user's Library folder is a parallel representation of the root level Library folder.

If your computer was working fine, and then suddenly something goes wrong, it's likely to be some file that was written recently.
Most of the stuff at the root level is read-only. Applications, fonts, system components, internet plug-ins, LaunchAgents -- these are very rarely written to or adjusted. Consequently, they're unlikely to be the cause of problems.

OK, there are some plists, system caches and temp files. However, user preferences and cache files are constantly being rewritten to, and this is where a lot of the work happens.

I know loads of Windows switchers who say "I reinstalled the OS twice, and it's still not working!" It's far quicker to test a new user account than it is to reinstall the OS as a method of locating the area where the problem is.

New user account ok: Look for problem in original user account.
New user account bad: Look for problem at system level.