[Samsung Galaxy Core.] AkashaWinds:
Hello, as the title says, I un-rooted my phone a few days ago... I used KingRoot, and I also used the Un-Root option on their windows app when I un-rooted my phone. I also used Root Checker App and the Terminal Emulator App from Google Play to verify, the results showed that my phone is no longer rooted.

Note: I'm also very newbie and most of the time, very clueless when it comes to these Android Rooting business, so I would appreciate it as well if the answers will be newbie friendly, and I apologize as well if I'm asking to be spoonfed for the solutions; I only have very limited time, and me hunting for answers in google resulted in hours of wasted time, except on me being able to learn just the meaning of a very few terminologies, too few to be considered significant I think.

~~(Might be helpful) Details:

-The model is: Samsung Galaxy Core Duos GT-I8262, and is running the Android Jelly Bean (Android Version 4.1.2)

-For a more detailed firmware/rom info (after dialing *#1234#):

AP: I8262XXAMG6

CP (Baseband Version): I8262DXAMH1

CDC: I8262OLBBMH2

Kernel Version:

3.4.0-1322246-user

dpi@DELL228 #1

SMP PREEMPT Mon Jul 22 17:26:39

KST 2013

~~Situation:

Now the thing is, the app I am using no longer allows phones who are rooted, so I un-rooted my phone, and to begin with, I haven't really done anything with my phone being rooted, since back then I was trying to fit my games on my external SD card by installing apps which requires root... but everything I tried with my limited time didn't work even with root, so I did not bother to do anything root-related (like installing certain UI modification and such). The only thing that got installed on my phone is this KingRoot app (which I prevented from installing any other app that it offered), and is since then removed.

Now, I un-rooted my phone using the Windows App that KingRoot provided, and I even used Root Checker app from Google Play and even checked my root status using the Terminal Emulator; results are all cleared, my phone is no longer rooted.

But when I run this app, it still gives me an error code that the devs themselves provided... an error code that indicates that my phone is either Rooted, is a China Phone, or other problems.

For the first two problems; Rooted or China Phone; I'm supposed to be cleared of this, and my phone is a Samsung bought from an official dealer...

As for the third problem: one of my friends who uses the same app told me that my problem might lie on my ROM not being a "Global" one... from the Firmware info I provided, I can see an area code called 'DX' (which should stand for Indonesia, Malaysia, Philippines, Singapore, Vietnam, and I am in the Philippines right now).

~~Problems:

There comes a whole lot of new problems, but first, to sum up my whole problem:

--What should I do with my phone to change its ROM or Firmware (what should I change between these two to begin with?) so that it becomes "Global" and would finally allow me to run this App (a Game), WHILE at the same time, still allows me to use my Sim Card in the country I am in right now and still being able to keep all my data intact (assuming Flashing a ROM would erase my phone's data particularly in the internal storage)?

Specific Problems:

-With my limited time, I only am able to find tutorials that allows one to flash a ROM using a Rooted Device... should I root my phone again and do the flashing then remove the root? And before that... really, what in the world should I do? (Refers to my question above on my problem summary), like, how should I flash this ROM while my device is unrooted, what should I do? (I'm really sorry for this question, but I hope someone will help me on this...)

-I am having dilemmas with backing up my data in my phone, such as my notes on the built-in Memo App, and my research said I have to use Titanium Backup... which requires a rooted device to work... can I just use this "Backup and Reset" from my phone's Settings and would still allow me retrieve my notes on my Memo App as well as my contacts and Text Messages intact after I flashed this "Global" ROM?

-I cannot seem to find a ROM that is "Global"(?) for my Smartphone Model and Android Version whenever I search google... can anyone of you who are knowledgeable enough provide me with such? Searching for it using google is not giving me any exact answers...

-I have read during my research earlier that when I flashed a ROM that is not in my country, my Sim Card would fail to work? Then what should I do to make this phone have this "Global" ROM/Firmware which will allow me to run this App, while at the same time, still allows me to use my Sim Card in this country without any problems?

-To begin with, from the data I provided:

AP: I8262XXAMG6

CP (Baseband Version): I8262DXAMH1

I see from the AP the area code 'XX' which denotes that it's Austria, Belgium, France, Germany, Hungary, Italy, Spain, United Kingdom, right? Then isn't my phone "Global" already? I'm very, VERY confused...

---

These are all the questions I have in my mind right now. I hope someone would help me with my problems, and clarify necessary things from my problem. If someone could also direct me to a tutorial of sorts, on flashing a "Global" rom that would enable me to run this App, while still making my phone's data intact and still allows me to use my Sim Card for communication purposes here in the Philippines, would greatly be appreciated as well.

Thank you all in advance, sorry for the long post too, I tried giving all the details I could and asking all the questions I could that might help pinpoint the problem as well as might help in providing me a solution that would work to fix my problem.