[tomseys]

I have an unlocked AT&T 640 GoPhone that I use with the T-Mobile pay as you go $3 a month plan.

I've disabled the LTE on it since 4G works just fine for me and I've read this can improve battery life.
I have been using the Win 8.1 it comes with and it works great.

I bought an extra 640 and I've been thinking about trying Windows 10 on it since people seem to really like it. So far, when I run the Upgrade Advisor, there is no Win 10 ready yet. My understanding is that I have to use the Windows Insider program to get Windows 10.

A few questions:

Are there any specific recommendations about how to use the Windows Insider program specifically and which version of Windows 10 to get?
I'm looking for something as bug-less, fast/good battery life and stable as possible.

Finally, briefly, what improvements exist in Windows 10 over 8.1? Anything worse?

Thanks!

[fdalbor]

Stay with 8.1 for awhile longer. It is possible, dispite what Microsoft says, the 640 will never get W10. With all the people they have working on W10 mobile it makes me wonder if Microsoft has lost its leading edge. I have a 640 I kept after I switched to Android, hoping it would get W10. But hope is fadeing fast, along with Microsofts market share. 8.1 works fine. Best leave it alone.

[Jamar Wright]

I love Windows 10 on my L640. At first I was very hesitant on using Windows Insider, because my 640 is my main driver. I didn't want it to have any major problems which would make the phone useless, ir buggy. These phone carriers in the US can take forever when releasing new software updates. So I've decided to live in the wild side a little lol, and go Insider. It was a wise decision! It runs very smoothly, and Windows 10 looks awesome! I'm glad I took the risk. It's worth it for all those in doubt. ☺

[Albatross2]

Get the Windows Insider app
Launch the app, enter the program, and switch to the Release Preview ring.
This will put you on the new 10586.242 release and it's very smooth and polished, suitable for your daily driver. I suggest you avoid the Fast and Slow rings for now as these would put you on the Redstone fork of the software which is still a little buggy due to many new features being added.

[tomseys]

Oh I meant to ask in the first post... say I don't like Win 10 for whatever reason, what do I have to do to go back to Windows 8.1?

[shikhanshu]

Oh I meant to ask in the first post... say I don't like Win 10 for whatever reason, what do I have to do to go back to Windows 8.1?

Download "Windows Device Recovery Tool". Google it, it's easy to find. When you install it, it will also install all Lumia drivers. If you want to go back to 8.1, simply connect the phone to USB, start WDRT, let it detect the device, it will tell you what firmware version is installed on your phone and which one WDRT database has (this will be same). It will also tell you the OS version (10.something on your device and 8.something on WDRT database).

Just do "Reinstall software" and your phone will be wiped clean (all data gone) and set back to 8.1 denim.

Do a backup before all this if you have anything to save.

[RumoredNow]

If you use Insider on the Release Ring, the same version is fetched as the recent public Upgrade received by these phones (10.0.10586.xxx): Phones Eligible for Windows 10 Mobile Official.

If your phone is not on the supported list, then 10586.xxx (Threshold) is the end of the line. You may as well use Insider and select Production to un-enroll your phone from Insider, but at least you have W10M. WaaS (Windows as a Service) will deliver future updates within Threshold to you without any Insider access required.

If your phone is on the eligible list and you go Insider and stay on the Release ring you get the next public version early as Release ring in effect is the RTM. This will deliver the most stable Redstone builds to you earlier than OTA push with minimal risk.

Check out this thread: http://forums.windowscentral.com/windows-10-mobile-insider-preview/421075-windows-insider-testing-you-%5Brecommended-guidelines%5D.html

For right now, Windows Device Recovery Tool is only flashing 8.1 to models that did not launch with 10 so it is the way to revert if you don't care for W10M: https://forums.windowscentral.com/e?...token=xYbF-qS5

[tomseys]

Okay, thanks for the info guys!

[kakashiax]

It is possible, dispite what Microsoft says, the 640 will never get W10.

Wrong, it will definitely receive the update.

[aybarrap1]

Wrong, it will definitely receive the update.

Yes the L640 in general may get it, but the carrier branded phones, such as the AT&T variant, may not as these phones and their owners are at the mercy of the carrier.

[realwarder]

640 runs Windows 10 fine. As others have said, Insider Production or Release Preview is the way to go.