The blog of Windows Wally, a Windows Support Technician helping common people solve frustrating computer problems.

How To Fix Error 80240020 In Windows 10 Installation

Reader Question:
“Hi Wally, I’ve been trying to install Windows 10 but it fails at “Preparing for installation”. Windows updates gives error 80240020. I’ve tried to find a solution to this problem, but so far nothing is working for me. the $windows.~BT folder on my computer is around 4GB its not 5GB. Its really annoying and I don’t know what to do anymore.” – Ryan H., USA

Before addressing any computer issue, I always recommend scanning and repairing any underlying problems affecting your PC health and performance:

  • Step 1 : Download PC Repair & Optimizer Tool (WinThruster for Win 10, 8, 7, Vista, XP and 2000 – Microsoft Gold Certified).
  • Step 2 : Click “Start Scan” to find Windows registry issues that could be causing PC problems.
  • Step 3 : Click “Repair All” to fix all issues.

Setting up weekly (or daily) automatic scans will help prevent system problems and keep your PC running fast and trouble-free.

Wally’s Answer: The Windows 10 update has been available for a few days and many people are trying to upgrade. Microsoft says that about 14 million devices were already running Windows 10 after the first day of its release. The free update is available for all Windows 7 and 8 devices till a year, so that would be about 29 July 2016.

If you’re stuck with the upgrade, then there are a few things that you can do to fix the error 80240020.


Although the update is out and people who have reserved their copies are downloading it, a few people are experiencing problems. This error is caused by unfinished and incomplete installation files. One reason for this is the excessive load on Microsoft’s servers hosting all these files. The error 80240020 problems should be alleviated in a few more days.


Here are some ways to fix error 80240020:

Delete The Folder To Force-Reset The Downloading Process And Fix Error 80240020

This way you can make Windows update re-download all the files, and hope that the Windows update will get it right. Here’s what you need to do:

  1. Browse to
  2. Delete everything in this folder.
  3. Press the Windows key > type cmd
  4. Right-click Command Prompt > click Run as Administrator
  5. In the command prompt window, type the following command and press Enter
    wuauclt.exe /updatenow
  6. Open Windows Update and try updating again. You should be able to get Windows 10 this time.

I Can’t Delete Those Files, Windows Won’t Let Me!

In case you were unable to delete the files in step 2 above, you will need to stop the Windows update service:

  1. Right-click Command Prompt > click Run as Administrator
  2. Run the following command in the command prompt:
    net stop wuauserv
  3. Now delete the files in:
  4. Right-click Command Prompt > click Run as Administrator
  5. Run the following command to start the Windows update service:
    net start wuauserv
  6. In the command prompt window, type the following command and press Enter
    wuauclt.exe /updatenow
  7. Open Windows Update and try updating again. You should be able to get Windows 10 this time.

Download Windows 10

If you’re still getting error 80240020, then you can try downloading Windows 10 and installing it yourself. Just make sure to “update” to Windows 10 when you launch the setup. This is really important because the “clean install” option is only for people who want to buy Windows 10.

Download Windows 10 by using the Media Creation Tool

I Hope You Liked This Blog Article! If You Need Additional Support on This Issue Then Please Don’t Hesitate To Contact Me On Facebook.

Is Your PC Healthy?

I always recommend to my readers to regularly use a trusted registry cleaner and optimizer such as WinThruster or CCleaner. Many problems that you encounter can be attributed to a corrupt and bloated registry.

Happy Computing! :)

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About the Author

Windows Wally is a helpful guy. It’s just in his nature. It’s why he started a blog in the first place. He heard over and over how hard it was to find simple, plain-English solutions to Windows troubleshooting problems on the Internet. Enter: Windows Wally. Ask away, and he will answer.