Windows users are prone to face the Blue Screen of Death errors and among them, one of the most frequently occurring errors comes up as APC INDEX MISMATCH on the computer screen. When this BSOD error hits your machine, it generates ‘Stop Code: APC_INDEX_MISMATCH’ message and urges the users to restart their PCs. Now, unless you resolve this blue screen problem and this error notification, Windows will not allow performing any task. So, if you are currently experiencing this index mismatch issue in your system’s APC (Asynchronous Procedure Call), go through this entire article. Here, it will discuss some of the main reasons behind getting this error code on your Windows. Also, if you want to remove this BSOD problem from your Windows 10 or any other Windows version, you can refer the solutions discussed here.
Why is your Windows Affected by the APC INDEX MISMATCH Error?
Basically, this APC function was meant to operate separately and outside the main program in Windows. However, it has the possibility of generating APC INDEX MISMATCH issue while running the boot process or after the booting of Windows is over. When your system gets this error, it points towards an inconsistency regarding the processes running on your Windows. Let’s now discuss a few other issues, which can trigger this blue screen error due to APC mismatch.
Causes which Relate to the Development of the APC_INDEX_MISMATCH Issue
When a driver or system file deals with disabling and re-enabling APCs along with mismatched call sequence, it can lead to this error condition. If the values in ‘CombinedApcDisable’ field are incorrect in either or both its ‘KernelApcDisable’ or/and ‘SpecialApcDisable’, it can lead to APC_INDEX_MISMATCH error.
Some users who have recently migrated to Windows 10 from other versions can also get this BSOD issue. This error usually occurs while operating the webcam on Windows 10 Skype application. But, according to some experts, this can happen when your device lacks the latest Windows Updates or have installed a buggy update.
In some cases, using an outdated graphics driver and other components can result in APC INDEX MISMATCH Windows 10 error. Also, look for the filename ‘Audiodg.exe’, which can cause this error if installed on your Windows.
Running the ‘DisplayLink Core Software’ on Windows 10 is another main reason behind producing error APC_INDEX_MISMATCH.
How to Troubleshoot APC INDEX MISMATCH on the Windows Based Devices?
If you don’t want to get stuck with the error code APC_INDEX_MISMATCH on your Windows, you can try the following fixes. However, you can take help from a technician to tell how to access the main screen before applying these solutions to resolve this BSOD error:
Fix 1: Run Windows in Safe Mode and Prevent Corrupted Drivers/Programs
The best method to fix the index mismatch in APC is by operating your Windows in Safe Mode. Then disable or uninstall the HD audio driver and follow technical instructions to install the new version.
Steps to Launch Windows in Safe Mode
For those who are using Windows 10, simply press ‘Windows logo’ and ‘I’ buttons on your keyboard. Otherwise, click on the Windows Start button and choose the ‘Settings’ icon. Next, open the tab of ‘Update & Security’ and select ‘Recovery’.
Now, go to the ‘Troubleshoot’ option by searching the term in the search box. Then click on ‘Advanced options’ and hit the tab for ‘Startup Settings’. Now, select the ‘Restart’ button and press ‘5’ or ‘F5’ when your device restarts. Finally, select the option of ‘Safe Mode with networking’.
Instructions to Disable Problematic Driver
After entering into the Safe Mode, you can stop the programs or drivers that can cause APC_INDEX_MISMATCH in Windows. So, if you suspect that the current version of HD audio driver or graphics driver is the reason, you can disable them.
To do this, open Windows Task Manager by pressing Ctrl, Shift and ‘Esc’ keys and click on the ‘Startup’ tab. Then, locate the HD Audio Manager and similar drivers from the list of startup items.
After locating the programs or drivers, hit the option of ‘Disable’ after right-clicking on them. Try to restart your system and check if it’s showing the message regarding Stop Code: APC_INDEX_MISMATCH.
Fix 2: Check for Recent Windows Update and/or Latest Drivers
Another great way to troubleshoot APC INDEX MISMATCH Windows 10 is by installing the latest updates. Yes, you need to do this both for your Operating System as well as the drivers, which can cause this error if outdated.
Apply Latest Windows Update
First, apply the steps discussed in the previous method to open the ‘Settings’ app on Windows 10. Then, find the option of ‘Windows Update’ below the section of ‘Update & Security’.
As you click on this tab, it will display some more settings on its expanded section on the right. Now, hit the ‘Check for updates’ button and make sure your device has a stable WiFi or Ethernet network to install the update.
After installing the Windows updates you can proceed to the following steps if getting APC_INDEX_MISMATCH message further. So, let’s discuss how to update important drivers on your Windows 10 to fix this problem in APC.
Instructions to Update Device Drivers on Windows 10
Remember, you will have to apply this method only if updating Windows doesn’t resolve the BSOD problem. So, follow the previous fix and make sure Windows 10 is running in Safe Mode.
Now, press ‘Windows logo’ button and ‘X’ key at the same time and open the ‘Device Manager’ window. You need to study the installed devices on Windows and identify outdated or problematic drivers.
So, look for the devices with an error mark (yellow triangle) next to them. Otherwise, you can take help from a professional and figure out which drivers need to be updated.
After getting the list of drivers that you want to update, select them one by one. Then right-click on it and select the option of ‘Update driver’. Hopefully, now your system won’t display the blue screen error or APC_INDEX_MISMATCH.
Fix 3: Remove DisplayLink Core Software Products
As discussed in one of the causes, enabling components from DisplayLink Core Software can also cause this APC error. Hence, you can check out the following steps to uninstall this program and its related products.
First, click on the Windows Start Menu and go to the feature of ‘Control Panel’. Now, view the list of programs and locate the icon of ‘DisplayLink Core Software’.
After selecting this option, select the tab for ‘Uninstall Program’. In case, Windows generates a dialog box to confirm the uninstallation of this software, click on ‘Yes’.
Then, it will show you the list of products that will get removed along with DisplayLink Core. So, hit the tab of ‘Yes’ and allow the uninstaller to delete all the DisplayLink Core Software components.
Finally, reboot your Windows 10 based computer and allow these changes to take effect. Hopefully, you will not see the BSOD error after restarting your system.
Fix 4: Turn Off BIOS Virtualization and/or Modify RAM Frequency
Apply this solution is the feature of Virtualization in causing interference with the APC settings. In case it doesn’t work, you can check the frequency of your device’s RAM and try to match it with the motherboard.
So, start with entering your Windows 10 into BIOS, which is possible only when you follow the boot sequence. During this process, simply hit the ‘F2’ or ‘Del’ button and your PC will enter into BIOS.
Then navigate through the settings on your Windows 10 and locate the Virtualization feature to disable it. For detailed instructions, you can refer to the motherboard manual or consult a Windows technician. If the blue screen error persists after disabling BIOS Virtualization, change the frequency of your RAM.
In order to match your motherboard frequency with the RAM, it requires advanced steps along with technical guidance. If you are not a tech-savvy person, it is recommended not to try these methods without consulting an expert. Now, if you are unable to resolve APC INDEX MISMATCH error message by referring to this article, get in touch with our Windows professionals.