Procedure to upgrade to windows 8.1 from windows 8 that worked for me.
- update all drivers and software
- cleaned cache (use ccleaner, windows 8 manager or some other cleaner)
- cleared Windows Store Cache, Windows key + R, type WSReset.exe, enter
- cleaned registry (use ccleaner, windows 8 manger or some other registry cleaner)
- Set any firewall or antivirus to full auto mode
- Reboot computer
- Remove all external devices possible
- Cleared Windows Store Cache again
- Download Windows 8.1 update and hope for the best.
