Background

UAC in an important security enhancement that Microsoft added to Windows Vista and above.

There is a lot of misunderstanding of what UAC does, and how to configure it.  This article will (hopefully) provide some insight into the UAC mechansim, and convince you that you should not change UAC settings from the defaults that Microsoft ships with.

What Exactly Is UAC?

Under UAC, certain areas of the operating system are locked down so only 'administrators' can access them.  These include certain areas of the Windows registry (e.g. HKEY_LOCAL_MACHINE) as well as areas of the file system (C:\Program Files\ for example).  To further complicate things, the concept of an 'administrative login' has changed quite a bit since the pre-UAC days.

When is an Administrator not an Administrator?

Under UAC, Administrative privileges are only granted to a user login that is *elevated*.  Generally speaking, elevation only happens with an explicit click on the UAC elevation 'Continue' button, such as in the following dialog:

Even if your user is part of the "Administrator" security group, an application you launch will not have true 'admin' privileges unless you approved the UAC dialog.

Disabling UAC Notifications (and why you shouldn't ever do it)

Windows provides a setting that allows you to control whether UAC prompts will be displayed or not.  To get to this dialog:

Windows 7 & 8: Control Panel->Action Center, then click the 'Change User Account Control Settings' link on the left side. 

Windows 10:  Control Panel->User Accounts, then click the 'Change User Account Control Settings' link in the center.

(Don't you just LOVE the way Microsoft moves these things around?)

This will present a dialog as follows:

If you drag the slider all the way to the bottom, you will no longer be prompted for UAC elevation.  However, and this is VERY IMPORTANT, this does NOT mean that you have turned off UAC.  UAC is still active - all you have done is removed the ability of the user to be notified that UAC elevation is required to perform the operation they are attempting to do.  This will cause applications to fail in strange and unusual ways.

We strongly recommend that you leave the UAC Notification slider in it's default position (as shown above).  Your software will probably not work properly if you change this.