Word Choice – Are ‘Not Enabled’ and ‘Disabled’ Same in Computing?

A noun phrase (NP) can be definite or indefinite:

• One way to mark an NP as definite is to use the definite article the.
• One way to mark an NP as indefinite is to use the indefinite article a.

A speaker marks an NP as definite when they assume the listener will be able to identify what the NP refers to. They mark an NP as indefinite when they don't make this assumption.

Some other words have semantics that are only compatible with either definiteness or indefiniteness. For example, same is definite; if you use it, you're specifying what the NP it modifies is referring to. There are two possibilities:

• Same can indicate that the NP refers to something previously mentioned. In this case, the listener must be able to identify what that referent is.
• Same can indicate that two or more things co-refer (meaning they refer to the same thing). That means the listener is able to identify what these things refer to (each other), even if they don't know anything else about them and they haven't been previously mentioned. That's enough to count as definite in English.

Since same only make sense in definite contexts, it can combine with the, and it can't combine with a. For this reason, *a same name is not standard English.

Be about [to VP] is a semi-modal expression, like be going [to VP] or be able [to VP]. It signifies that VP is expected to happen in the very near future, and that the discourse concerns that expectation. How near will depend on context.

John was about to sit down to dinner when the phone rang. ... This suggests that John was actually moving toward the dinner table and the action was interrupted by the phone ringing.

Rumours that Microsoft is about to announce Office for iPad were current on the internet, in exactly those words, for at least three weeks before the actual announcement.

I am about to start graduate school. ... This might be said weeks or months before you actually plan to start graduate school. It suggests that you have been accepted by a school and your discourse will involve preparing to start.

ADDED:
As Bob Rodes points out, about here has the sense, “nearly, almost”. In other contexts it acts as an adverb: I am about ready = “I am almost ready”; but in the idiom be about [to VERB] it cannot be paraphrased this way: *I am almost to go is not English. And in the idiom it never has other main sense of about = “approximately, around”.