How come mine doesn't auto update?

Hi all, I'm still figuring one the HTC One (M7) that I got, and I'm pretty new to this so I apologize if my questions are basic, and I would really appreciate your help! I looked through a ton of material on this forum and other websites, and been exploring my phone but I haven't gone to unlock the bootloader or flash anything yet, since I am worried about the repercussions of doing something wrong and bricking my phone.

Long story short, I bought my phone off Amazon, its an AT&T unlocked version, and I recently found that this meant I cannot make use of the hotspot tethering function. If it matters, I am primarily going to use my phone in Singapore.

Here's my phone info:

My first question is:
My software version is stated as 3.17.502.3
However on the HTC website for HTC One ATT version it says the latest software version is 5.12.502.2
But when I run the AT&T Update on my phone, it says that no updates are available.
Why is this so...

The second question is related to the first:
Since I am going to use the phone primarily in Singapore, should I just flash it to a non-ATT ROM, which would presumably remove the 'lock' on tethering? If I choose to do this, do I need to change the CID (using SuperCID or other means) to enable me to flash to another ROM? I just need the vanilla HTC Sense without all the useless ATT add-ons.

Thanks for your help!

yatindroid said:

Ok custom Rom will cover your every need
ARHD MaximusHD are custom Rom based on stock Rom & not modified much & don't have crap carrier add on
So you have to unlock boot loader install custom recovery
Install custom Rom
I saw your hboot still on 1.55 so get S Off using firewater it will so much beneficial

& you're not happy with custom Rom then you can convert it to any other country Rom
Unlocking boot loader
Install custom recovery
Install root
S Off
Change CID according to your needs
Change MID according to your needs
Flash stock ruu exe or ruu zip according to your needs
That's it

from HTC One

Click to expand...

Click to collapse

Thanks for your reply...
i actually spent the whole night up last night figuring it out and reading all the info here and other sites.
In the end I managed to
unlock bootloader
install custom recovery TWRP
install root SuperUser
flash to Android 4.4 KitKat Sense 5.5 (stock from HTC)

it seems to be working okay and i did not need to S-off or change CID/MID (which i feared would result in bricking, since those seemed much more advance)
I took a small gamble since my Hboot was 1.55 and i didn't know how would differ from other versions which the guides used, but so far it seems like things are alright.

was a fairly steep learning curve since this is literally my first smartphone and I had no idea about 85% of the jargon.. but after a while I managed to figure most of it out haha.

but really appreciate your help too! thanks!