As of October 2016, Microsoft has contracted with B2X to provide a variety of assisted support services for Nokia, Lumia, and feature phone devices. On the B2X site, you can choose the support option that is most convenient for you to resolve your issue.
October 2019 update
Support for Windows Phone 8.1 operating system ended on July 11, 2017. As a culmination of the end of support process, the Windows Phone 8.1 Store will shut down on December 16, 2019. Lumia phones using Windows Phone 8.1 and any apps that have already been downloaded from the Store may continue to work after this date. However, users may experience a further reduction in functionality as follows:
Users will not be able to download any additional apps to the phone. Users should make sure to download all applications that they might want before December 16, 2019.
There may be some degradation in app functionality going forward as updates are no longer available via the Store. Users should check with app publishers if they have questions.
Reinstallation of apps will no longer be possible. If a user removes an app from the phone it will not be possible for such app to be restored. This includes phone reset as well as use of the Windows Device Recovery Tool (WDRT) where apps are deleted or removed. Users should take this into consideration before choosing to reset the phone or use WDRT on or after December 16, 2019.
Certain Lumia phone models can be upgraded to Windows 10 Mobile. Users who choose to upgrade an eligible device should note that Window 10 Mobile is already out of support or, in some cases, will be by the end of 2019. This means the operating system will no longer be updated (including no additional security updates), though the Store is currently still functional.
The following Lumia models are eligible for the Windows 10 upgrade:
Microsoft Lumia 430
Microsoft Lumia 435
Microsoft Lumia 532
Microsoft Lumia 535
Microsoft Lumia 540
Nokia Lumia 635 (only 1GB RAM variant)
Nokia Lumia 636
Nokia Lumia 638
Microsoft Lumia 640
Microsoft Lumia 640 XL
Nokia Lumia 730
Nokia Lumia 735
Nokia Lumia 830
Nokia Lumia 929
Nokia Lumia Icon
Nokia Lumia 930
Nokia Lumia 1520
Some exceptions to this list are possible depending on mobile operator variant or region. Check with your mobile operator for more information.
Over-the-air upgrade to Windows 10 Mobile requires Upgrade Advisor application that can be downloaded from the Windows Phone 8.1 Store. Users must download Upgrade Advisor before December 16, 2019 if they want to use this option. Upgrades can also be performed with Over-the-Cable (OTC) Updater PC tool if user do not have the Upgrade Advisor app.
Potential buyers of Windows Phone 8.1 Lumia phones should be aware that as a result of the Windows Store shutdown and the discontinuation of support services, the phones will have reduced functionality and customer support will be limited.
An FAQ for Windows Phone 8.1 lifecycle can be found here
March 2018 update
Microsoft has released a software update for the Nokia 215, 216, 220, and 222 phones sold in Turkey. This update addresses an issue with answering incoming calls from certain 3-digit numbers. In all other respects, the new software functions the same as the version currently on your phone.
Warning: This update will erase all of the personal data from your phone memory. Memory card is not erased. Make sure to back up your contacts and other important content before you install the update.
Record or back up your contacts and other important information from your phone.
On your PC, download the Nokia Software Recovery Tool (NSRT) tool.
Follow the on-screen prompts to install the tool, then select Launch application.
Use a USB cable to connect your phone to your PC. The phone must be powered on and charged. The tool should automatically detect your phone.
Follow the instructions in the tool to download and install the new software.