Present perfect vs present perfect continuous tense

[PetriF258]

Good day

I just want to make sure I understand something correctly. Let's take the following example:

1) The new computer software has been installed: This means that the new software has been installed and the effect of the installation remains, i.e. the installed software is still on the computer.

2) The computer software was installed: This means that the software was installed but we do not know whether this software is still on the computer.

3) The computer software has been installing ...: This means that the installation started in the pas and the software is currently still installing.

Would I use has or was when the time of the installation is unsure? For example: The computer sotware has been / was installed 5 months ago. Or would I apply the above mentioned rules?

Thanks

[RonPurewal]

with a specific past time point, you have to use the past tense; you can't use "has/have ___ed".

in any normal context, the reason for this sort of thing will be amply clear.

e.g.,

I went to Hong Kong in 1994, when it was still under British rule.
––> past time point; "went" in past tense.
the point of this sentence is to describe something that happened in 1994-- and not (for the moment) to relate it to the present in any direct way.

I have gone to Hong Kong, so I know what the weather there is like.
––> relevant to the present; "have gone".
i think you can see why it would be rather stupid to mention "in 1994" in this sentence.

[RonPurewal]

as for #3, technically, you still have to use a passive construction; it's nonsense to say that the software "installs" (itself?), so it's likewise nonsense to say that it "is installing"-- same problem.

so, technically, the correct form would be "has been being installed".
now this is a stylistic problem, because good writers don't use "has been being ___"--not for any logical reason, but simply because it's awkward.
rather, a good technical writer would find some work-around, e.g., "has been in the process of installation", "has been undergoing installation", etc.

obviously, not all writing is held to such high standards; in a casual chat or informal blog post, you might well see "has been installing". in a technical document--nope.

[RonPurewal]

and you're exactly right about #1 and #2.

[PetriF258]

Perfect

Thanks for the quick response.

[RonPurewal]

you're welcome.