Causes & Resolutions For The “0XC004D401” Error In Vista

The “0XC004D401” error inside Windows Vista is a problem caused by the validation and authentication of your PC. This error is typically seen randomly when you are using your Vista PC and is actually quite simple to fix.

Causes Of The 0XC004D401 Error

If you’re receiving the 0XC004D401 error, you’re probably seeing it along with this message: “Error 0XC004D401: The security processor reported system file mismatch error” or “Error 0XC004D401: unrecognized error“.

The error is typically caused when the antivirus or other security software is not compatible with Windows Vista. Also, these errors are typically seen as the cause of this problem as well:

• Corrupt registry settings
• Corrupt system files
• Incompatible antivirus / security programs

Fixes For The 0XC004D401 Error

Step 1 – Disable / Uninstall Current Antivirus / Security Software

If you’re using antivirus or some other security software to help keep your computer protected, then you should disable or uninstall it immediately. This is because the main cause of the 0XC004D401 error is the way in which some antivirus programs or firewalls block access to the Vista authentication system, making your PC think your computer is unregistered. You should first disable your security software and if that solves the problem, you should uninstall it completely; seeking an upgrade from the developer.

Step 2 – Perform A System Restore

If you have only recently started to see the errors, you should look to perform a “system restore” to roll your computer back to the status it had before it was erroneous. To do this, you should click on Start > All Programs > Accessories > System Tools > System Restore. This will bring up a system restore panel, where you can then select the date which you would like to revert your computer back to. You should pick the most recent date that was before the errors. After doing this, your computer will restart and have your old settings… and should be rid of the error. However, if it does not work, try step 3:

Step 3 – Run A Registry Scan

– Download This Registry Cleaner

The registry is a big problem for Windows as it stores a vast number of important settings and files for your PC. These settings are required continuously by Windows in order for it to run smoothly, but the problem is that many of them become damaged and corrupted, leading your computer to run extremely slow and with errors. One of the main causes of the 0XC004D401 error is the way in which the security / authentication settings for Vista can become damaged and lead your PC to run extremely slowly. Fortunately, you can use a registry cleaner to fix this. Registry cleaners are software tools which scan through the Windows registry and fix any of the damaged or corrupt settings that are inside it. You can download our recommended registry cleaner below: