Short answer: very well indeed. My personal Lumia 1020 is now on the Creators Update and, with only a couple of caveats, I'm very happy with it there now. Skype is now supported again (the new UWP version), I get the newer versions of all the Microsoft first party apps, all the latest third party UWP apps are now viable and very little feels abandoned.
The prerequisites (if you're considering doing the same as me, here, though do read right to the end for loads of caveats) are:
- an older non-W10M-approved Windows Phone 8.1 device, ideally with 1GB RAM or more (e.g. Lumia 920, 1020)
- a Windows 7, 8 or 10-running PC
- unlimited free time and patience - really!
I'll save the usual disclaimers and caveats - if you're attempting any of this, along with me, then you're technically skilled and well aware of the risks. And if you're not, then run a mile - just buy a newer phone! I also can't emphasise the last point enough - it took me around 48 hours, on and off, working my way through the updating procedure, with several blind alleys and trial and error (and resets). With this feature, you may be able to halve this time, but it's still not a quick process!
I also want to emphatically emphasise that I'm not going to be tech support for anyone else following in my footsteps. Try the steps I used and see how you get on, but if something comes unstuck and you hit a problem then sorting it out is part of your own learning curve!
If you're happy to proceed then read on. The first set of steps is from this XDA Developer page, with extra comments from me. See that link for the downloads needed though.
1. I downloaded and opened the main package (see source link, which may be a URL string that needs pasting into a browser tab), then opened it in 7-Zip. I extracted the exact folder from it (in this case the named folder '768x1280'). (Again, see the source link for exactly which folder to extract for each phone, if you're confused.)
2. Using Win(Command)+R, in the run command dialog, I typed "control printers" and then ran this. It's the familiar Devices and Printers pane, but you apparently need to bring this up in order to remove the phone manually. I'm not 100% sure why this step is needed, but I guess it forces the OS to re-recognise the phone below?
3. I downloaded and extracted the 'iutool' package (again, see the source link above). From Windows Explorer, I right clicked and started a new command (PowerShell in my case, on Windows 10) window.
4. I plugged the phone into my PC, and then typed: '.\iutool.exe -l'.
The PowerShell console then confirmed that 'Nokia 909' (the Lumia 1020's original model name) was connected and available.
5. I then typed this command: 'iutool -V -p D:\768x1280' (or whatever path you put the phone CAB files in!)
6. After about 20 minutes (with minimal activity on the PC screen, somewhat scarily - make SURE your PC doesn't time out and go to sleep!), my Lumia started spinning cogs, cue another long wait, up to an hour! Again, if you're following all this, make sure the PC stays on, the utility is still in control! After all this the 1020 booted into Windows 10 Mobile 10586.107, i.e. Threshold, one of the earliest W10M branches.
If the phone hangs late in the update process (e.g. at the 'Migrating' stage) then it's safe to disconnect and power the phone off and then on again. It should finish the final migration steps and then you'll be booted as 'normal'!
Note that, as with any other new or newly reset Windows phone, it's best to wait half an hour at this stage, while all the applications re-install from the Windows 10 Store.
7. Having started the phone, I found that the on-screen keyboard didn't work at all! Which is a right pain because you can't then type in (for example) a Wifi password. The source link does mention this, though it means another download and side-load. I downloaded 'Internal_IME.zip' and extracted the cab file for 'en-gb', renaming it as instructed to '123.cab' (I assume that this could have any name, the 'cab' bit is the important one).
I then installed this too with 'iutool -v -p D:\123.cab' (ignore the '8024a110' error) and the Lumia rebooted and started updating itself shortly, with the usual cogs and 'migrating' steps. Patience is again needed... Following the update, my keyboard was working fine again, so I was able to set up the phone on Wi-fi and verify that Windows 10 Mobile (10586 branch) was now in place and working.
8. On the phone, I went to 'Settings/Update & Security/For developers' and selected 'Developer mode'.
9. I grabbed the old Windows Phone 8.1 SDK application deployment utility, filename WP8.0 SDK Tools Lite Setup Av1.20.zip on the PC. Once downloaded, I extracted it all ran the .bat file supplied. This also took a while (loads of components are involved) and I needed to approve permissions every so often.
10. Still on the PC, I downloaded the vcREG registry editor. It's a file ending in '.xap'.
11. On my Start menu, I ran the Windows Phone 8 Application deployment tool. I selected 'device' and picked the registry editor .xap file that I grabbed just now:
12. With my phone connected and the screen turned on and unlocked, I clicked on 'Deploy'. Nothing appeared to happen, but the status showed as 'Complete' after a few seconds and then vcREG appeared in the apps list on the phone.
13. I ran vcREG, tapped on the '...' menu and then on 'templates'. I checked 'Live Interop' and 'Restore NDTKsvc' and then on 'Apply'. My old Lumia 1020 was now 'jailbroken', to use the iPhone jargon. And the registry was unlocked:
14. Back on the PC, I downloaded 'Interop Tools' from the here, I went for downloading the stable v1.7, since I had issues with newer versions (v1.9 of the app would crash with no useful information - probably something I'd done wrong, but hey).
15. Using Explorer on my Windows PC, I copied this Interop Tools folder tree into a suitable area on the phone, e.g. 'Downloads'
16. Back on the phone, I ran (Windows 10) File Explorer, navigated to /Downloads and then tapped on each of the 'dependency' files in turn. These are libraries needed and they install silently in the background. I waited a few minutes to be sure and then tapped on the main Interop Tools application installer - and, again, waited a minute for the background installer to do its work. I then ran 'Interop Tools' and headed into the Registry Browser.
17. I navigated through (in turn, i.e. 4 taps) the registry key hierarchy:
18. I then changed the phone's ID so that when the phone update routines come calling, it reports itself as a device that's most definitely 'allowed' to get the latest OS updates. I used the Lumia 950 XL for the ID:
- I set 'PhoneManufacturer' to 'MicrosoftMDG' (capitalisation is important). I tapped on 'Write' and then 'Write' again.
- I repeated along the same lines for 'PhoneManufacturerModelName', to 'RM-1085_11302' (or RM-1116_11258 has been suggested for dual SIM devices, again mimicking a Lumia 950 XL)
- I repeated for 'PhoneModelName', setting this to 'Lumia 950 XL'
19. Heading to 'Settings/Update & Security/Phone update', I found that Windows 10 Mobile OS branch 14393 was already downloading, as the next step for the Lumia 950 XL. This is the Anniversary Update and I waited the usual hour or two while this installed, the phone restarted and 'migrated', and so forth.
20. So far so good, and my test Lumia 1020 was now far more up to date. Now for the latest and most satisfying part - grabbing the Creators Update (a.k.a. Redstone 2, branch 15063). Now the rollout for the 950 XL for Creators Update isn't total yet across the world, so I went down the most sensible route and used 'Settings/Update & Security/Windows Insider Programme' to set this Lumia up to receive 'Release Preview' ring updates.
21. I headed back to 'Phone update' and there was the Creators Update downloading and then installing. On (in this case) a 2013-made Lumia 1020!
22. It's at this point that I'd recommend a full 'reset your phone' in Settings/System/About. I didn't need to, above, because my Lumia 1020 had already been reset about a dozen times during the 48 hour experimentation period. But if you've come up via 8.1/Threshold/AU and haven't yet had a chance to reset then now is the time. And don't try and restore any 'backups'. Just resync your data in the usual way and re-install any applications needed from the Store/My library. The OS will be cleaner and fresher that way and everything will work more reliably - trust me.
23. As usual, in the Store there will be a lot to update. So be patient! On the older, slower Lumias, you're looking at about an hour to install 50 UWP app updates - and you'll need to keep an eye on it too, as it can get paused while the Store client itself closes or gets updated.
Do note that there are some caveats to taking an older phone like this through to Windows 10 Mobile 'Redstone 2' (and beyond):
- You can't always use the camera in Skype UWP - the camera hardware is usually somehow locked to other camera applications, even if not running still - it seems as if this is Skype being over-fussy!
- Brightness is stuck on 'Auto' - not a huge deal, since most people leave it on this anyway, but....
- Glance screen is gone, since all the registry keys that the older phone hardware need are moved competely for Redstone. Potentially another showstopper for some?
- Windows 10 Maps is broken, in that the map rendering code was updated in the latest versions to use hardware-accelerated graphics in the newer chipsets - using Maps on older x20 Lumias on Creators Update results in road outlines not being drawn properly. Navigation still works fine, including voice, but it's disconcerting to see much of the familiar Maps interface 'missing'!
- On the Lumia 1020, the familiar 5MP/34MP 'dual capture' is missing, by default, since Windows 10 Camera does things differently. In fact, this app is very limited on the 1020 because you can only shoot in 34MP/38MP mode - far too high for most practical purposes. However, all is not lost, since the UWP applications ProShot and 1Shot fill the gap admirably and I'll be featuring these in another feature this week on AAWP. Update: Lumia Camera is now back in the Store for the 1020 under CU!
Performance is smooth but slow, as you might expect on such an old device. Starting applications can take a second or two and there's definite 'lag' by 2017 standards, yet at no point do things stop working or appear overly impractical. If you want the camera functions (via those third party UWP apps), including zoom and Xenon, then it's perhaps worth living with an older, slower phone?
The 4.5" 768p screens do seem small by today's standards, yet consider the use of capacitive controls - these mean that you never have to live with virtual, on-screen controls, and so the effective interface is equivalent to a 5" screen with the latter.
At the very least, the Lumia 920, 925 and 1020 can live on the Creators Update on the whole and take part in most of what Windows 10 Mobile has to offer in 2017.