Here’s how to fix PC error code 99

Andrew Wafer
by Andrew Wafer
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If you try to boot or reboot your Windows device but you get stuck on a black screen with the error code 99 displayed at the bottom right corner, it means that something isn’t functioning as it should.

No, it’s not a Windows system malfunction, but a hardware issue which is preventing the OS from loading properly and that’s why the boot/reboot sequence cannot be completed. Simply put, the Windows OS cannot be initiated.

The debug 99 code is not even an actual error. It shows what stage it’s currently running and in this case we are discussing about problems within Super IO Initialization.

In a few words, the debug code 99 is talking about an issue related with the boot process and more particular with the master hard disk. Of course, the motherboard can cause the issue, but it might be something with the BIOS setup too.

Anyway, we will try to find the proper fix for PC error code 99 in this article.

How to fix PC error code 99

If you can go to BIOS you should start the troubleshooting process by ensuring that the SATA mode is set into AHCI instead of IDE. Moreover, the boot order should follow the UEFI protocol by default.

You can also verify the Time and Date from BIOS and you can even choose to reset or update CMOS as this can easily fix the error code 99.

Do note that depending on each manufacturer the BIOS options might differ. Updating BIOS without booting into Windows is possible only for newer motherboards while making a reset can be done by accessing factory settings.

You can also reset the motherboard by removing and re-applying the BIOS battery, though this is a complex process which will imply in disassembling your PC, so be careful and try not to mess things up even worst.

Hint: don’t be afraid to ask for a more experienced help if you are not a tech expert.

Other troubleshooting solutions to apply:

  • Verify the supply cables and make sure that HDD SATA is properly connected.
  • Check all the other connections from your motherboard and make sure that everything is working by the book.
  • Go to BIOS and check if the HDD is detected or not; if the HDD isn’t shown you might have a faulty HDD.
  • Disconnect the peripherals before initiating a new reboot – just remove any external devices attached to your Windows device.
  • Try to boot up only the motherboard – unplug everything else, beside your keyboard. Also, remove RAM and anything else that might not be required for an initial boot (including audio and USB from motherboard). Note: sound cards and nic cards should be also disconnected.
  • If you built your own PC, make sure that everything is connected as it should and that you didn’t forget anything else. Again, don’t hesitate and ask for an experienced opinion, depending on your own system configuration.

As already outlined, the debug code 99 describes Super IO Initialisation issues. So, the fixes should focus on this particular field.

We hope that managed to fix this problem with with the help of the solutions listed above.

Editor’s Note: This post was originally published in October 2017 and has been since completely revamped and updated for freshness, accuracy, and comprehensiveness

Editor's Note: This article was originally published in October 2017 and was revamped and updated in April 2019 for freshness, accuracy, and comprehensiveness.
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