This has only been tested by myself on a small, old 3DS on 8.1, 9.0 and 9.4, but it's reasonable for this to work on any console. Feedback is obviously appreciated!

1. Completely power off your system.
2. Boot in recovery mode (press L+R+A+↑+Power, hold the first four about 1 second, more won't hurt the system but only your fingers... )
3. It will ask you as usual to update. However, it will take a little longer for the screen to come up compared to the speed it would have had if you didn't already have an update.
4. If you click yes, the update will be completely redownloaded then installed...
5. If you click no, it will power off and you'll go home free!

Update 2017: Yes, this is only for sysnand (although you can hack the import.db of a nag-free sysnand's internal storage onto emunand through Decrypt9 or similiar ways, check out specific tutorials), because no CFW implements the launching of emunand's recovery mode!

This is also unrelated to the forced updates for YouTube or the browsers bundled with 9.9+, and neither it resets the "update available for this app" text
on the Home launcher!

 

[Apache Thunder]

Uh oh. This seemed to work for me all day today, but once again it popped up the stupid nag
I've noticed though, that even if the update data is deleted (system update selection from system settings says ready to download update from internet) it will still pop up the nag ocassionally. Perhaps I misunderstood the topic though, and that's all you meant for this to do. Argh, I just want to get rid of the nag...

I've also noticed that Nintendo only enables the nag for some versions of the firmware. For example when I accidentally downloaded 9.0 on my 8.1 2DS (confirmed it via system update in system settings) but it never nagged me about it. But when it accidentally downloaded 9.4 it started nagging me right away.

The update nag will eventually return if you don't keep it off the internet or use a DNS filter on router/proxy to block the update servers.

 

[psvpwner]

The update nag will eventually return if you don't keep it off the internet or use a DNS filter on router/proxy to block the update servers.

Yeah I understand that of course and I've kept it offline. I haven't even enabled Wi-Fi since I used the trick.

 

[DjoeN]

Working really well
Few Whole days almost of 3DS XL usage, short periods off, long periods off, and for the last days, no update nag screen.

Thanks

 

[Pedeadstrian]

Thanks. I was reluctant at first but it did the trick. I have to keep the internet on for the Gateway browser exploit, but I quickly open up the browser after starting, so I should be good for a long while.

 

[Aliahan]

Awesome!
This must be what that one asshat was trying to ransom to get his "friend" unbanned here. He tried to ransom it at a certain ISO forum, too.

If we always keep the 3DS running in 9.5 emuNAND it shouldn't download the update again even we enable Spotpass, right?

 

[zoogie]

Hate to rain on anybody's parade but the update remained for me after performing the trick. Simply advancing the clock one day ahead and connecting to the internet for a brief moment triggered the nag prompt.

 

[Pedeadstrian]

Hate to rain on anybody's parade but the update remained for me after performing the trick. Simply advancing the clock one day ahead and connecting to the internet for a brief moment triggered the nag prompt.

What do you consider a brief moment? I did this trick over two days ago. I've been playing my 3DS every day, while connected to the internet for the browser exploit, and have yet to see the nag again.

 

[spinal_cord]

I think I'll be leaving my wifi settings blank from now on. I'm happy to stay on 9.2 forever, unless a new hb loader emerges for newer firmware.
This is very useful indeed :-).

 

[luney]

Seems to have worked! Great job! Thanks for the heads up.

Edit:
Unfortunately it did not stop the nag to update my game though. I currently have no internet at all in my home(work iPad has internet) since my cable was turned off last night. Will removing the game, load another, then put the previous game in prevent that nag?

 

[zoogie]

What do you consider a brief moment? I did this trick over two days ago. I've been playing my 3DS every day, while connected to the internet for the browser exploit, and have yet to see the nag again.

3-4 seconds. Not enough time for a 70MB+ download on a 10mbs connection.

The update never gets deleted with the trick.

 

[Pedeadstrian]

Seems to have worked! Great job! Thanks for the heads up.

Edit:
Unfortunately it did not stop the nag to update my game though. I currently have no internet at all in my home(work iPad has internet) since my cable was turned off last night. Will removing the game, load another, then put the previous game in prevent that nag?

That update nag won't go away until you update it. Just download a .cia of the game update online.

 

[JoostinOnline]

Do you mind if I repost this on another forum as long as I give you credit?

 

[Ryccardo]

Wow this is super useful! Thanks for the info, how did no one know about this before?

The button combo was documented on 3dbrew, I guess nobody wanted to try something which only apparent purpose is to install an [unwanted] update in this condition... and those who did either just clicked yes, didn't notice the effect or just weren't bothered to report!

So simple it almost made me laugh BTW is this a flaw in the system, should we expect this to get patched?

Don't think so, it can be useful to recover from a corrupted download that always fails installing (if that's even possible with the truckload of checks it probably has).
More worrying (for a Japanese "Kyoto" megacorp) is that this can be used to access network settings without knowing the password (press yes with wifi off, or just away from any configured networks and Nintendo Zones), thereby breaking a flagship feature on which multiple paper sheets and megabytes are wasted -- maybe that's why they started not including chargers!!

recovery menu is *usually* a function within the bootrom (already loaded before the firmware is loaded)

Partially, it just sets certain memory areas depending on button presses; the actual handling of them is at higher levels (so it can't activate when SSB4 reboots the system, for one)

Do you mind if I repost this on another forum as long as I give you credit?

Of course, knowledge should spread freely anyway!
As for everyone who had the popup back: I've never experienced it when I waited 4+ days to install 9.5, then again nobody appears to know how this is actually implemented...

 

[psvpwner]

Here's how I think it works:

If your 3DS downloads an update Nintendo has marked as critical, it will start showing the nag, otherwise it will just sit there but never notify you about it. However if you delete the update (which this trick seems to do) the nag will stop showing as long as you switch your Wi-Fi off (because it can't tell you that it's ready to start the update when the local file is deleted and it's not connected to any access point).

Even if you have Wi-Fi enabled and you're connected to your Wi-Fi router which you have blocked your 3DS with, the 3DS still remembers that it has seen a critical update available (even though the local data is deleted) and it thinks it's online (it says "Internet" in the upper right corner of the home menu for me when it's connected to my access point even though I've completed restricted internet access for my console), it will go on with the nagging.

 

[migles]

this worked for me. the update and even the blue notification light about the update didnt come back so far

now i kinda miss it :C not sure whats the point on keeping at 9.4 but there is no reason to update it anyway...

 

[Ryccardo]

now i kinda miss it :C not sure whats the point on keeping at 9.4 but there is no reason to update it anyway...

It's a gamble, I went to 9.3 and on since I wasn't going to buy Cubic Ninja but we all know what came out afterwards...

 

[NyaakoXD]

...It was that simple? lol

 

[Jayro]

After 48 hours, the nag to update hasn't returned on my 9.2U 2DS, so thank you OP.

 

[Adr990]

Thanks for this!

Working great!

 

[nastys]

Could someone try if the browser works after removing the nag?