I am not able to update apps in my Windows phone. When I go to store it is showing error. I am not able to back up also. If I reset my phone I will lose my contacts & messages. Help me please.
If you have an older Windows Phone 8 device, it is no longer supported. As I recall this means that the Windows Phone 8 app store is also no longer available. Windows Phone 8.1 also ended support in July 2017. Please see https://support.microsoft.com/en-us/help/4036480/windows-phone-8-1-end-of-support-faq
Contacts should be in the cloud somewhere depending how you set your Live account and whether you linked it to outlook.com or not. Email should be in the cloud as well on which ever email account you linked to your device e.g. Gmail, outlook.com etc.
As Neville has said it is no longer supported. This does not mean the phone will not function but if the phone If the phone is new, sone apps on the phone would not work like facebook, twitter, sports, news, BBM, Windows store and so on.
I am currently using a windows phone 8.1 but I cant open this apps I listed above and some other and I cant even open a Microsoft account through the settings but can open gmail and others but not also Nokia account. I did some research and found out that there is no more support for thus device but after the end of support, an update was sent for does who still want to use the device.
This link will help you know how to update your device if you can download apps http://www.google.com/url?q=https://blogs.windows.com/windowsexperience/2016/03/17/upgrading-existing-windows-phone-8-1-devices-to-windows-10-mobile/&sa=U&ved=2ahUKEwjKptm9qoL0AhVPb30KHe66DGsQFXoECAUQGw&usg=AOvVaw12ppSWZN94R40t6jWvHkSK
But if you cant download apps like me then this link should tell you how to update Over The Cable(OTC) using the file OtcUpdaterZip.exe. Here is the link https://handsontek.net/update-windows-phone-8-1-windows-mobile-10/