Fix: Task Sequence Failing with Error 0x800704900

Getting a 0x80070490 error when trying to install Windows, usually when imaging, means that your BIOS is having problems with the partitions on the hard drive.

This is also an issue when you’re using the System Center Configuration Manager from Microsoft, in order to reinstall Windows on a device, which is frustrating due to the number of users having this issue. This happens regardless of the Windows version you’re trying to install, and on both laptops and desktop PCs. There have also been cases where users reported this happening when BitLocker is activated, but for those who need it, disabling it is not an option and they need another solution.

Fortunately, there are a couple of things that you can do to solve this partitioning issue, after which you can go ahead and install or reinstall any version of Windows you need. A universal tip before you go to any of them, however, would be to disconnect any other storage devices from your computer, as they may be confusing the BIOS and that might be the reason it’s failing.

Method 1: Set the boot options to UEFI

There are some devices which go to a BIOS boot by default, and that is causing them to give you this error, and fail to install Windows. Fortunately, the solution is fairly easy, and the steps below will help you even if this is the first time you’re entering the BIOS.

1. Restart your computer.
2. Before Windows boots, you will see the POST screen. Look near the bottom, there are should be a button combination that you can press to enter the BIOS. It’s different for all manufacturers, but it should be something along the lines of Esc, F2, F12, or Backspace. Make sure to press it quick, before Windows starts booting, because otherwise you will have to restart it again.
3. Inside the BIOS, look at the bottom or right side of the screen. That is where the manufacturer of your BIOS will have placed instructions on which button does what on your keyboard, and you will need to use that for navigation.
4. Using the buttons, find the Boot options
5. In the Boot options menu, there should be an option to switch between BIOS and Set it to UEFI.
6. Use the instructions about the navigation to Exit with saving changes, and reboot your device. It should be working just fine now, but in case it isn’t, move on to the next method.

Method 2: Switch the drive controller to AHCI

This method will help you if for any reason, your BIOS controller is set to anything other than AHCI, such as SATA or RAID if you have multiple hard drives.

1. Using steps 1 through 3 of the previous method, enter your device’s BIOS
2. Within the BIOS, find the Controller mode Set it to AHCI mode.
3. Exit with saving your changes, and reboot. Your BIOS shouldn’t have issues recognizing everything now, and the install will go smoothly.

Given the simplicity of imaging Windows from a USB or a hard drive compared to a clean install, it is no surprise that a lot of users have opted for this step. It is also much quicker, and therefore more efficient when trying to install Windows on multiple devices at the same time. If you’re having this issue, follow the steps above to solve it, and you will be able to continue with the process.