The “Unknown Hard” error that keeps on appearing in Windows 10 can put users in an unpleasant situation. This kind of error leads to the freezing of the taskbar, blackening of the screen, and sudden disappearance of the icons on the Desktop. And each time you try to open Windows, the system will only give you an error message saying that it’s a critical error and some applications like Start and Cortana won’t work.
Upon analysis, it seems that the “sihost.exe” is not responding and that it is the one that’s causing the c000021a Unknown Hard error to pop up. Sihost.exe files represent the Shell Infrastructure Host which is an essential component in the Windows operating system. The Windows Shell Infrastructure Host is primarily responsible for handling some graphical elements of the operating system interface such as the Start menu and the taskbar transparency. And so if the Shell Infrastructure or Sihost.exe has stopped, has been removed, or corrupted, you will most likely have issues with the overall functionality of the Windows operating system and you’ll get the Unknown Hard error
In addition, the ctfmom.exe Unknown Hard error may also occur due to incompatible drivers installed on your PC. Ctfmom is a process that identifies inputs such as handwriting, languages, and many more. It’s the one that controls the functions of background behavior. To resolve this issue, you need to first try to identify which application is the one that’s running the sihost.exe file. And if needed, you need to either update or reinstall or completely uninstall the problematic application.
The SFC Scan or System File Checker, us a built-in utility in Microsoft Windows that can be found in the C:\Windows\System32 folder. This tool allows users to scan and restore any corrupted system files in Windows that might be causing the Unknown Hard error to appear. Before you use this tool, make sure to find out whether the sihost.exe on your computer is a Trojan that you have to remove or if it’s a file that belongs to a trusted Windows application. Once you have that sorted out, follow the steps below.
The command will start a system scan which will take a few whiles before it finishes. Once it’s done, you could get the following results:
You can also try using System Restore. This is one of the ways you can use it to back up your PC. Since restore points are created automatically each week by System Restore, you can use System Restore to restore your computer back to an earlier good point in time.
Putting your PC in a Clean Boot state can help you diagnose and troubleshoot the issues in your system. During this state, you can start the system with a minimum number of drivers and startup programs that will surely help you in isolating the root cause of the Unknown Hard Error.
After putting your PC in a Clean Boot State, try creating a system restore point and see if the problem still occurs. Clean Boot troubleshooting is designed to help you isolate the problem. For you to execute a clean boot troubleshooting, you must do a couple of actions (the steps are given above) and then restart your PC after every action. You might have to disable one third-party app after the other to really isolate the issue. And once you’ve narrowed down the problem, you can either disable the third-party app that’s causing the problem or remove it. Note that you must switch your PC back into the Normal Startup mode after you’re done troubleshooting the problem. Here’s how you can do it:

Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options
Well if anyone told me just a few years ago that I will see the day when Microsoft releases a new OS based on Linux I would be very amused, but that day has come. Mariner is the newest OS out of nowhere.
Microsoft’s new Linux Distro, dubbed Common Base Linux (CBL)-Mariner, isn’t the type of distro you’d want to install directly on any old machine. It’s primarily meant for cloud infrastructure and edge products. Specifically Microsoft’s Cloud and Edge products.
But if you are curious, it’s possible to run. Juan Manuel Rey, a Microsoft Senior Program Manager for Azure VMware, recently published a guide to ISO CBL-Mariner image. With that, you can easily get it up and running. And you can build CBL-Mariner on an Ubuntu 18.04 desktop. So you can try it out since it is free.
You can get it from here: https://github.com/microsoft/CBL-Mariner
It is obvious that Microsoft aims to set itself as a leader in enterprise server environments with this move and it is very likely that it may succeed or at least give a good shake to its competitors, mainly red hat and Suse which are two dominant distros in that field.
Many believe that they can win over by providing regular updates and package delivery via their already established system and that feature could be a turning point for some.
In any case, time will tell and we shall see. One of the problems encountered by Windows users when upgrading to Windows 10 from Windows 7 or Windows 8/8.1 is the Error Code 0x80070020. This error code normally occurs when users try to download updates from the Windows Update Website or simply by upgrading to Windows 10. Error Code 0x80070020 also occurs when the device already has a Windows 10 installed.
Once this error is encountered, it will cause malfunction of update installs and display the following message:
An error (-5006 : 0x80070020) has occurred while running the setup. Or The process cannot access the file because it is being used by another process”
In an attempt to fix Error Code 0x80070020, it is important to pinpoint what the cause is. The most probable cause of this error is due to interference. This error code most likely occurs when there is another automatic update running, for instance, an Antivirus scanning in real-time. If you’re scheduled to have an automatic update during real-time scanning, the Windows 10 update might malfunction.
In trying to fix Error Code 0x80070020, you can perform manual repair methods to resolve the issue effectively and efficiently. Most Windows users can easily employ these manual repair methods, even those who do not have technical abilities. However, there are certain instances where a Windows professional’s help is needed. If you don’t want to face any risk in resolving the issue, it would be best to consult a professional Windows technician or you can also make use of a powerful automated tool.
NOTE: It is best to attend immediately to errors encountered since unresolved errors can result in slowing down your computer’s performance. This might also cause other error messages to arise such as Error Code 0x80070057.
Since Error Code 0x80070020 is most likely encountered due to interference during your update, the easiest method you can do is to close all opened programs and restart your device. After restarting, try to start the update process again.
Another quick and safe way to fix Error Code 0x80070020 is to disable your antivirus. You must take note though that in doing so, your computer will be susceptible to virus attacks. If you want to proceed with this method, follow these steps:
The Windows Update Troubleshooter may resolve many of the errors encountered by Windows users when installing updates from Windows Update. To execute the troubleshooter, follow the steps below:
Executing a clean boot means starting Windows using only a few resources, including startup programs and drivers. This safeguards minimizing conflicts and prevent software clash when an update is received. In performing a clean boot, you will be able to pinpoint what caused the manifestation of error code 0x80070020. Check Microsoft’s Support website to know how to execute a clean boot.
Performing this method is a bit risky and should be your last option if all methods were unsuccessful. This process will alter your device’s registry so you must ensure to perform accurately the steps. A single mistake can lead to modifying your registry erroneously, which might result in the occurrence of other error messages. Carefully follow the steps found on Microsoft’s Support website to successfully reset Windows Update components.
Resetting Windows Update components can also be done by implementing the following steps:
A third-party antivirus such as BitDefender may recognize the Windows Update as a threat since the new update of Windows 10 is probably not yet registered with this third-party antivirus vendor. To solve this, you must disable temporarily the antivirus before performing the update. Once the third-party antivirus is disabled, you can now proceed with the updating process. Update as well your third-party antivirus.
The Deployment Image Servicing and Management (DISM) is a command-line utility that is installed by default in Windows 10 system. This program is used to fix images in Windows. In the case of Error Code 0x80070020, the DISM can repair the recovery image in Windows 10 and can perform as a virtual hard disk as well.
/CheckHealth – to check for corrupted files or components
/ScanHealth – to check for corrupted Windows image. This may take up to 10 minutes to finish
/RestoreHealth – to check for corrupted Windows image and do an automatic repair. This may take up to 20 to 30 minutes to finish
NOTE: In an instance where you cannot locate the good files in your computer, the system image files may be corrupted. If this happens, you need to have a copy of install.wim from a computer with good Windows 10 OS or the Windows 10 ISO file. Make sure that the source of the good files has the same language, version, and edition of your OS.
Enter the following commands one by one to perform the /RestoreHealth switch using the source path location of good files you copied:
For example purposes, the “repairSource” is the source of the good files.
ExpressFiles is a program developed by Express Solutions. A number of Anti-Virus programs have flagged this program as a Potentially Unwanted Application. In many instances, it is bundled with additional programs on installation.
The program claims it offers users easy to search for various currently popular search terms. During our testing, the software never displays any search results, no matter the search words. Upon installation and setup, it defines an auto-start registry entry which makes this program run on each Windows boot for all user logins. A scheduled task is added to Windows Task Scheduler in order to launch the program at various scheduled times. The program defines an exception rule in Windows Firewall, allowing it to connect to the internet without limitations and auto-update itself.
SearchApp by Blpsearch is a Browser Hijacker that is presently targeting Google Chrome browsers. It is offered as a tool gives user enhanced online search experience. Search App also has other amazing tools that let you quickly search the web from a new tab window.
This extension changed your home page and new tab search to blpsearch. While installing you will see additional ads and sponsored links displaying throughout your browsing sessions. It collects user browsing information and uses it to better serve sponsored content.
Digital Signature/Publisher: Bandoo Media, Inc. Product Version: 5.0.2.4762 Entry Point: 0x000038AF