The document provides 9 steps to fix Error Code 21 in Windows 10. It begins by describing common symptoms of the error such as program crashes and slow performance. Potential causes include corrupt software installations, registry issues, viruses, and outdated drivers. The 9 steps to resolve the error are: 1) use a registry cleaner, 2) conduct a malware scan, 3) clean temporary files, 4) update device drivers, 5) use System Restore, 6) uninstall/reinstall related programs, 7) use the System File Checker tool, 8) install Windows updates, and 9) perform a clean Windows reinstallation as a last resort. Contacting the provided toll-free number can also help get assistance from a certified Windows support professional

1. Call us: +1-800-201-4243
Visit us: https://microsoft-help-numbers.com/
How To Fix Microsoft Windows
Error Code 21 – 9 Steps
Solution
Symptoms of Error Code 21 and How to Get Help in Windows 10 to Fix
It
• “Error 21” appears and crashes the busy program window.
• Your Computer regularly crashes with Error 21 when running the Same app.
• “Windows Error Code 21” is now displayed.
• Windows runs smoothly and reacts slowly to mouse Keyboard input.
• Your personal computer occasionally ”freezes” for a few seconds at a time.
All these 21 error messages may appear during program Setup, while a
Microsoft Corporation-related software application (eg. Windows) is
currently running, during Windows startup or shutdown, and even during the
installation of their Windows os. Learn how to get help in Windows 10
keeping an eye on when and where your windows error code 21 occurs is a
crucial item of advice in troubleshooting the issue.
Causes of Error 21
• Corrupt incomplete or download installation of Windows Computer software.

2. • Corruption in Windows registry from a Current Windows-related Software
alter (install or install).
• Virus or malware disease that has corrupted Windows system Files or
Windows-related app files.
• Another app maliciously or inadvertently deleted Windows-related files.
Runtime Errors for example “Error 21” could be brought on by a Number Of
variables, so it is essential that you troubleshoot each of the probable causes
to keep it from recurring.
How to get help in Windows 1o to
Fix Error 21
The below mentioned are the troubleshooting measures to fix Your Error 21
problems. Need to realize these troubleshooting steps get progressively
harder and time-consuming, so we strongly suggest attempting them in
ascending sequence to avoid unnecessary time and effort.

3. Step 1: How to get help in Windows 1o –
Repair Registry Entries Connected with Error
21
Manually editing the Windows registry to remove invalid Error 21 keys isn’t
advised unless you are PC service professional. Incorrectly editing your
registry can stop your computer from functioning and create permanent
injury to your os. In reality, one lost comma will prevent your PC from
booting entirely!
Because of this danger, we highly recommend using a trusted Registry
cleaner such as Win Thruster [download] (Developed by Microsoft Gold
Certified Partner) to scan and repair any signs 21-related registry problems.
Utilizing a registry cleaner [download] simplifies the process of finding
invalid registry entries, overlooking document references (like the one
causing your 21 error), and split links within the registry. A backup is
automatically generated before each scanning, with all the ability to undo any
changes in one click, protecting you against the possibility of PC damage.
The best part is that repairing registry errors [download] can also
dramatically improve system speed and functionality.
Caution: Unless you an advanced PC user, We Don’t recommend Tracking
the Windows registry. Using Registry Editor incorrectly can cause serious
problems that might require you to reinstall Windows. We do not guarantee
that problems resulting from the incorrect use of Registry Editor can be
solved.

4. How to get help in Windows 10, learn manually to
mend your Windows registry, first you need to
Make a backup by exporting a part of the registry
linked to Error 21 (eg. Windows):
1. Click on the Start button.
2. Kindly type ”command” in the search box… DO NOT hit ENTER yet!
3. While holding CTRL-Shift keys on your keyboard, hit ENTER.
4. You will likely be prompted with a permission dialog box.
5. Now, click Yes.
6. A black box will be opened with a blinking cursor.
7. Type in here “regedit” and hit ENTER.
8. In the Registry Editor, then Pick the Error 21-related key (eg. Windows) you
want to back up.
9. From the File menu, then choose Export.
10. In the Save In list, choose the folder where you would like to save your
Windows backup key.
11. Now have a look in the File Name box, type a name for your backup
file, for example, “Windows Backup”.
12. In the Export Range box, be certain that ”Selected branch” is selected.
13. Click on Save.
14. The file is then saved using a .reg file expansion.
15. Now you finally have a backup of your Windows-related registry entry.
The following Upcoming measures in manually editing your registry will not
be discussed within this article as a result of high chance of damaging your
system. If you would want to find out more regarding manual registry
editing, please see the links below.

5. Note: We don’t assert any responsibility for the outcome of these actions
taken from the articles related below – complete those tasks at your personal
risk.
Step 2: Conduct the Full Malware Scan of
Your Computer
There’s a chance that your own Code 21 error could be associated To a
malware infection in your PC. These malicious intruders can damage,
Corrupt, or even disable Device Manager Errors-related files. Moreover,
There is a possibility that the 21 error you are experiencing is associated with
a Component of the malicious app. How to get help in Windows 10 is a
frequently asked question from the users and these all steps are the answers to
fix the problems in most of the cases.
Step 3: Clean Out Your System Trash
(Temporary Files and documents)
Over time, your personal computer accumulates junk files from ordinary Web
surfing and computer usage. Whether this junk isn’t sometimes washed
outside, it may cause Windows Operating System to respond slowly or has an
Code 21 mistake, possibly because of document conflicts or an overloaded
hard disk. Clearing up these temporary files with Disk Cleanup may possibly
perhaps not only fix your 21 error, but can also significantly accelerate the
operation of your PC.
(cleanmgr) tool, we highly recommend using a specialized hard drive clean
up / privacy protection software such as Win Sweeper [download]

6. (Developed by Microsoft Gold Partner) to tidy up your entire computer.
Running Win Sweeper [download] once a day (using automatic scanning)
will ensure that your computer system is clean, running fast, and totally free
from Code 21 errors linked to temporary files.
How to get help in Windows 1o to fix the error
code 21, kindly go through the below-mentioned
instructions:
1. Kindly click the Start button.
2. Type in “command” in the search box… DO NOT hit ENTER yet!
3. Now keep holding CTRL-Shift keys on your keyboard, hit ENTER.
4. You may probably be prompted using a permission dialog box.
5. Please click Yes.
6. A dark box will start with a blinking cursor.
7. Now, type “cleanmgr” and hit ENTER.
8. Disk Cleanup will begin calculating how much occupied space you can
regain.
9. The Disk Cleanup dialog box may appear with string of check boxes you may
select. In many cases, “Temporary Files” category occupies the most disc
space.
10. Look at the boxes of those categories that you wish to wash and
click OK.
Step 4: Update Your Own Personal Computer
Device Drivers
21 error can be related to outdated or corrupt device Drivers. Passengers can
operate a single afternoon and suddenly quit working the next day, for an

7. assortment of reasons. The good news is that you may often upgrade the
device driver to resolve the Error 21 problem.
Choosing the Specific driver to the Error 21-related hardware Device can be
exceedingly hard, even entirely on the Microsoft Corporation or related
manufacturer’s web site. Even if you’re proficient at finding, downloading,
downloading and manually updating drivers, then the process can still be
time intensive and extremely irritating. Hiring the wrong driver, or only an
incompatible version of the perfect motorist will make your problems even
worse.
Because of the sophistication and time involved with upgrading Drivers, we
recommend using a driver update tool like Driver Doc (Manufactured by
Microsoft Gold Partner) to automate the procedure.
Driver Doc upgrades all of your PC device drivers, not just Those connected
with your 21 error. Driver Doc’s proprietary One-Click Update™ technology
not just helps to ensure you have correct driver variants for the hardware, but
additionally, it creates a backup of your existing drivers prior to making any
adjustments. Maintaining a driver backup provides you with the security of
knowing that you can roll back any driver to a previous version if necessary.
With upgraded device drivers, then you can finally unlock new hardware
features and improve the speed and operation of your personal computer.
Take Note: Your Error 21 Might Not Be related to hardware Motorist
complications, however, it’s almost always a fantastic idea to guarantee most
your PC device drivers are up to date to optimize PC performance.

8. Step 5: Present System Changes
Windows System Restore lets you ”go back into Time” along with your PC
to help mend your Error 21 issues. System Restore can extend your personal
computer’s system files and programs straight back to a period when
everything was working alright. This may potentially help you avoid hours of
migraines associated with 21 errors.
Please notice: Using System Restore will not affect your Documents, images,
or other data.
In order to use the System Restore (Windows XP, Vista, 7, 8, and 10):
1. Click the Start button.
2. Type in the search box, “System Restore” and hit ENTER.
3. From the outcome, click System Restore.
4. Input any administrator passwords (if prompted).
5. Observe the steps from the Wizard to pick a restore point.
6. Restore your PC.
Step 6: How to get help in Windows 1o-
Uninstall and Reinstall your Windows
Program Related to Error 21
In case your 21 error is related to a Particular program, Reinstalling
Windows-related applications may possibly be the solution.
Basic troubleshooting Instructions for Windows 7 and Windows Vista:
1. Kindly open Programs and Features from clicking on the Start button.

9. 2. Click the Control Panel on the right-hand side menu.
3. Now, click Programs.
4. Click Programs and Features.
5. Presently, locate Windows Error Code 21-associated app (eg. Windows)
below the Name column.
6. Click the Windows-associated entry.
7. Click on the Uninstall button at top menu decoration.
8. Adhere to the onscreen instructions to finish the uninstallation of one’s own
Error 21-associated program.
Directions for Windows XP:
1. Open Programs and Features by clicking the Start button.
2. Now, click Control Panel.
3. Click on Add or Remove Programs.
4. Locate Windows Error Code 21-associated program (eg. Windows) below
the listing of Currently Installed Programs.
5. Click the Windows-associated entry.
6. Click the Remove button on the perfect side.
7. Follow the on-screen directions to finish the uninstallation of one’s own Error
21-associated program.
Guidelines for Windows8:
1. Hover the cursor at the bottom left of the screen to make the Start-
Menu image.
2. Kindly Right-Click to bring up the Start Context-menu.
3. Click on Programs and Features.
4. Locate Windows Error Code 21-associated program (eg. Windows) under
the Name column.
5. Presently, click the Windows-associated entry.
6. Click the Uninstall/Change on the top menu decoration.

10. 7. Follow the onscreen instructions to complete the uninstallation of
one’s Error 21-associated program.
How to get help in Windows 10 to fix error code 21? Kindly follow the
above-mentioned instructions else contact technical support as Windows 10
settings may vary as per to the compatibility of the user’s device.
Once You have successfully flashed your Error 21-associated program (eg.
Windows), re install the program in line with this Microsoft Corporation
directions.
Tip: In case You’re positive that your 21 error is related to some Special
Microsoft Corporation application, uninstalling and reinstalling your Error
21-related application will probably be the remedy to your problem.
Step 7: Run Windows System File Checker
(“sfc /scannow”)
System File Checker is a handy tool as Well as Windows That enables you
scan for and restore corruptions in Windows system files (for example those
associated with Error 21 ).
How to get help in Windows 10 to run System File Checker :
1. Kindly click the Start button.
2. Type “command” from the search box… & DO NOT hit ENTER yet!
3. Keep holding CTRL-Shift keys in your computer keyboard, hit ENTER.
4. You may get a permission dialog box.
5. Now, click Yes.
6. A dark box will open with a blinking cursor.

11. 7. Type “sfc /scannow” and then hit ENTER.
8. System File Checker will begin scanning for Error 21 as well as other system
document problems (The system scan may take a while).
9. Adhere to the on-screen commands.
Step 8: Install All Available Windows Updates
Microsoft is constantly upgrading and improving Windows System files
which may possibly be associated with Error 21. Sometimes resolving your
Runtime Errors problems might be as easy as upgrading Windows with the
latest Support Pack or alternative patch which Microsoft releases in an
ongoing basis.
To check for Windows Updates (Windows XP, Vista, 7, 8, and 10):
1. Click on the Start
2. Kindly type “update” into the search box and hit ENTER.
3. The Windows Update dialog box will prompt.
4. If updates are available, kindly click the Install Updates
Step 9: How to get help in Windows 1o-
Perform a Clean Installation of Windows
In order to prevent data loss, you need to make certain you have backed up
all of your important documents, pictures, software contractors, along with
different personal data before beginning the approach. However if you aren’t
currently copying your data, then you need to perform so immediately
(download a highly-recommended backup solution). As a result, you guard
yourself against the permanent data loss.

12. This measure is your ultimate choice in trying to resolve your Error 21 issue.
Reinstalling Windows will eliminate all out of your Hard Drive, enabling you
to start out back with a fresh system. Furthermore, a clean Install of Windows
will even quickly clean out any and all “crap” Which has gathered over the
normal usage of your computer.
Read also: How to get help in Windows 10 to fix an error 0x80246008?
Take Note: If 21 mistakes still persist following a Clean install of Windows,
your Runtime Errors problem has to be hardware related. If This Is the case,
then it is likely you will need to substitute the associated Hardware inducing
the 2 1 error.
Hope the post help!
Need help? Contact Windows 10 support number toll-free at +1-(800)-201-
4243 and get instant technical assistance from Microsoft Windows Certified
Professional for Windows Computer round the clock.