ErrorFix 400 Bad Request 
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400 Bad Request description

400 Bad Request Definition: 400 Bad Request is a failure of your computer to send an incorrectly formatted message. 

400 Bad Request Error is a common Windows error. 400 Bad Request is usually caused by missing system files, wrong system settings or a corrupted registry fileRun a registry scan to check for registry errors & other system problems. 90% of the time this will fix the cause of the error.



Have you encountered this error as well? Read about possible solutions to 400 Bad Request errors on this website. If you don’t find a fix for your case here, sign up for our 400 Bad Request newsletter and we will add information on possible fixes and prevention for your particular case. Let’s free ourselves from 400 Bad Request errors together!

As a rule, you get the 400 Bad Request error message when your internet browser is trying to send or receive a message that has not been formatted correctly. Also, the 400 Bad Request error code may appear in other different error messages, depending on the software you are trying to start or install or the action you are trying to execute on your computer. The most typical causes for the ‘400 Bad Request’ error are a faulty RAM or device driver, incorrectly written, installed or updated software, malware applications or even Windows security features.

Below are some examples of 400 Bad Request error messages and possible resolutions. However, if you are not a computer technician we strongly advice to contact an expert on this issue or use professional software (you can find some resources on this website).

What causes the 400 Bad Request?

Variations of 400 Bad Request

  • HTTP 400 - Bad Request
  • 400 Bad Request
  • Bad Request 400
  • 400 Bad HTTP Request
  • HTTP Bad Request 400
  • 400 Bad Request Error
  • Bad Request Error 400
  • Error 400 Bad Request
  • 1.1 400 Bad Request

How to fix 400 Bad Request - Registry Cleaner

The 400 Bad Request error is usually caused by a lack of maintenance of your computer and corrupt registry keys that slowly yet surely pile up as you install and delete programs, especially when you install new programs over old ones that were not deleted fully. To get rid of the 400 Bad Request error you could attempt to go through each and every one of the registry entries manually but this would prove to take a lot of time and be exhausting. If you are not a computer expert the manual registry would take your over a week. In addition, if you make mistakes while changing registry entries there is a chance you'll make things even worst by damaging important registry records. If you are not a PC nerd then use special professional software to repair your registry.

We recommend  ErrorFix Registry Cleaner:

This award-winning computer tool is used by experts and recognized by magazine editors as the world’s top registry cleaner. It is one of the fastest and most user friendly registry cleaner for Windows that safely cleans, repairs and optimizes your registry in three simple steps. Read more about ErrorFix Registry Cleaner.

How to fix 400 Bad Request - Antivirus

Your computer may have a virus and the 400 Bad Request error informs that the system prevented the virus from connecting to the internet to it's writer. The next time you may not be so lucky and the 400 Bad Request error will not appear, instead you'll have an even worst error. Just to be on the safe side we know for sure that if the cause of the 400 Bad Request error is a virus then the MicroAntivirus will detect and remove it:


We recommend to use internationally award-winning Micro Antivirus.

Read more about the Micro Antivirus Here

How to fix 400 Bad Request - Memory Optimizer

The 400 Bad Request message can some times appear as a result of your computers physical and virtual memory being corrupt. The 400 Bad Request error will also appear if it needs to be seriously optimized. In this case the software we recommend to use that will not only fix the 400 Bad Request error but also improve your computers speed massively is:

The Memory Optimizer by MemAgent:


Read more about MemAgent's Memory Optimizer here. 

How to fix 400 Bad Request - Driver Update

Sometimes 400 Bad Request error occurs when your current printer profile doest not match the updated settings of windows or one of the programs you are trying to use. In such cases you can try to reinstall the program, printer drivers or even the entire system many times but that just won't solve the problem. This is because each time you will install the same default user profile included in your printer installation package by the creator of the program. In such cases the easiest way to fix the 400 Bad Request error to use the Driver Robot:

Read more about updating your systems drivers with Driver Robot Here.

How to fix 400 Bad Request - Antispyware

Your computer might be infected with spyware and the 400 Bad Request error is a message that appears when it tries to use your browser to to upload your private files to the internet. In such cases we definitely recommend installing the Reimage AntiSpyware product to remove the 400 Bad Request spyware error:

Get rid of the 400 Bad Request error - scan your computer for free right now!

How to fix 400 Bad Request - Antimalware

If the 400 Bad Request is a result of Malware and not spyware then the official Malware Removal Bot is what you need:

We have seen a few cases where the Malware Removal Bot removed the 400 Bad Request message.

The Malware Removal Bot comes with a free edition - give it a try.

How to fix 400 Bad Request - Internet Explorer Fix

If the internet explorer itself is the root cause of the 400 Bad Request error and you have the latest version installed but still the message appears then you should try the RegTool software. It has an Internet Explorer repair functionality that can fix the 400 Bad Request issue:

Click Here to give RegTool a try!

How to fix 400 Bad Request - Dll Fix

The 400 Bad Request error is rarely caused as a result of a corrupt Dll file. In such cases you need the RegTool fixer as well in this case to fix the 400 Bad Request problem.

How to fix 400 Bad Request -  Windows Firewall Application

If you want to prevent the 400 Bad Request virus\spyware\malware from communicating over the internet with other hackers or want to prevent it from infecting your computer then you need the best firewall application available on the internet today - Firewall Gold:

Come check out the official Firewall Gold website for more information...

How to fix 400 Bad Request - File Recovery Program

Many times the 400 Bad Request error appears as a result of deleting many system critical files or other files.

You can use Restore My Files:

It can retrieve files that you accidentally deleted. It fully restores them and gets rid of the 400 Bad Request message.

Come check how to restore your files here.