BACK UP YOUR DATA
Check for the Windows 8.1 upgrade on the Windows Store (use this link on your Windows 8 PC if needs be - ms-windows-store:WindowsUpgrade). Hit the download button and you'll be taken back to the Store home screen. Problem? Not at all. The app is actually downloading the release in the background. Just sit tight, make a cup of tea and it'll progress along steadily.
Windows 8.1 will then alert you that apps may need to be re-installed after the upgrade is complete. Hit continue for the install progress to continue preparations, or cancel to quit. It may appear as though nothing is happening, this is normal. This enables you to get on with things quickly until the install requires you to reboot.
Wait until the system prompts you to reboot. It's not recommended that you shut down or reboot your PC while the installer is running in the background
Once the installer is ready to progress to the next step, you'll be asked to reboot. Do this and the setup will begin installing Windows 8.1 on your PC. This may take a while.
If the issue is still not fixed, it can be a very critical problem with your computer affecting your personal data and the Windows Operating System. You will have to chat with our Experts or you can check with your local technician to get the problems fixed with very high priority.