Support for Windows update issues. Windows operating system often shows several errors due to virus attacks,update failures and file system corruptions. Get help from our experts to fix the Error code 0x8004fc12. Update error code 0x8004fc12 in Windows 10/8/7: This Error Code 0x8004fc12 is commonly caused due to the .NET framework installation failure. These are following ways in which you can attempt to correct this error. Disclaimers: Before you attempt to fix an issue with the windows update, we highly recommend you to take a registry backup and create a system restore point as a precaution method. In case if something goes wrong, we can restore your computer to the same stage and fix the issues. (In case if you not sure how to back it up, talk to an expert for assistance.) This .NET Framework 3.5 for Windows 8 or Windows 8.1 won’t come with pre-installed .Windows 8, Windows 8.1 or Windows 10, and must be separately enabled to run applications that depend on it. So enable the .NET Framework 3.5 in Control Panel to avoid Error code 0x8004fc12 . Note: Make sure you have set correct Date and time on your computer, try to install pending updates through other available networks. Run windows update troubleshooter. https://www.winchatsupport.com/0x8004fc12-windows-update-error/