FIX: LockAppHost.exe uses a lot of memory in Windows 10

Ivan Jenic
by Ivan Jenic
Troubleshooting Expert
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  • The original LockAppHost.exe is system file and an important part of Windows. It rarely causes problems but if it's start hogging on memory, it's a sign of issues.
  • The first step would be to restart LockAppHost service and if that doesn't work, a good idea would be to perform a SFC scan to check for corrupted files.
  • RAM is a very crucial resource for your computer so it's important to know how to manage it. Please go to our Computer memory tips and guides section to find more information.
  • For any problems or information about Windows 10 visit our Windows 10 fix hub where you can also find a lot of solutions to your possible problems.
How to fix LockAppHost.exe high CPU

Various things could cause a high memory usage not just in Windows 10, but also in all previous versions of Windows.

This time, a couple of Windows 10 users complained online about how they found out that the LockAppHost.exe process is causing high memory usage without any particular reason.

So in this article, we’ll try to solve this issue, as we prepared a few possible solutions for memory leak in Windows 10, caused by LockAppHost.exe.

How can I prevent LockAppHost from using a lot of memory?

  1. Restart LockAppHost service
  2. Run SFC Scanner
  3. Check for viruses
  4. Lock and unlock your computer
  5. Disable Windows 10’s lock screen

Solution 1 – Restart LockAppHost service

Simple restarting LockAppHost process could potentially solve the problem, so that’s what we’re going to try first. To restart LockAppHost process, do the following:

  1. Go to Search, type services.msc, and open Services
  2. Find LockAppHost service, right-click on it and go to Properties
  3. Click on Stop, and then click on Start again
  4. Restart your computer, and see if LockAppHost is still eating your memory

If restarting the process didn’t get the job done, we have a few more old school solutions for you.

Solution 2 – Run SFC Scanner

SFC Scanner is old Windows’ own tool for diagnosing and solving various system-related problems. So we’ll try to use SFC scanner to solve our problem, as well.

To run SFC Scanner in Windows 10, do the following:

  1. Right-click on the Start Menu, and go to Command Prompt (Admin)
  2. Enter the following line and press Enter: sfc/scannowlockapphost problem windows 10
  3. Wait for the process to finish (it might take a while)
  4. Restart your computer, and see if the problem is resolved

Solution 3 – Check for viruses

Some IT experts often connect high CPU usage caused by LockAppHost with a virus, or some kind of other malicious software.

So, it won’t hurt if you run your antivirus program and completely scan your system for any suspicious activities.

If you don’t use an antivirus program on your computer, scanning your system with Windows Defender can also get the job done.

But if you want a deep, more detailed scan, some third party software is probably the best option.

If you still didn’t decide which antivirus program you want to use, check out the list of the best antivirus programs for Windows 10, it will certainly help you to make the right decision.

Solution 4 – Lock and unlock your computer

If LockAppHost.exe is draining your computer memory, try locking your device and then log back in. Many users confirmed that this basic workaround helped them solve the problem.

I have the same problem, and the last time I investigated it seemed to have something to do with the lock screen modal. I locked my machine (Win + L) and re-logged in, and it went away

Solution 5 – Disable Windows 10’s lock screen

This solution requires a bit of patience, but some users confirmed it works, so it’s worth trying it.

By disabling Windows 10’s lock screen you can resume your Windows session much faster and jump straight to the log in screen.

Here are the steps to disable the LockApp folder:

  1. Launch File Explorer > navigate to go to C:Windows > SystemApps > Microsoft.LockApp_cw5n1h2txyewyMicrosoft.LockAp
  2. Right-click on the folder > select Rename.
  3. Add .bak to the end of it the folder name > hit Enter.

Keep in mind that this solution doesn’t permanently remove the lock screen. When you reboot your PC, the lock screen will be there, but it won’t appear when you wake it up from sleep.

That’s about it, I hope at least some of these solutions helped you reduce the high CPU usage on your Windows 10.

If you have any comments, or questions, just reach for the comments, below.

FAQ: Read more about LockAppHost

  • What is LockAppHost EXE?
The LockAppHost.exe is a system file and an important part of Windows. It rarely causes problems and it is a trustworthy file from Microsoft. However, if you’re in doubt, here’s how you can fix corrupted system files.
  • What to do when LockAppHost.exe uses a lot of memory?

The first step in fixing this problem is to restart the LockAppHost service. If you don’t know how to do that, follow our expert guide to fix the issue.

  • Does locking windows 10 stop processes?
Locking the screen doesn’t kill applications, so they should still be there and running when you unlock it. So no, it doesn’t stop processes.

Editor’s Note: This post was originally published in February 2018 and has been since revamped and updated in March 2020 for freshness, accuracy, and comprehensiveness.

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  • As an instant work around, I locked and unlocked my machine (Win key + L) and that stopped the CPU blitz (credit to Redditor:tomogotes).