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(SOLVED) Why your Disk Usage is Too High (at 100%)

Why is my disk usage so high?

Your Windows disk usage can be very high because of low virtual memory, a virus threat or third-party software conflicts.

  • Low virtual memory
  • Virus threat
  • Third-party software conflicts


Low virtual memory

Sometimes when the virtual memory of your system is very low, it considers the disk as the RAM to clear off the temporary files. This can cause errors on the pagefile.sys system file and spike the disk usage. The only way to resolve this issue is to reset the virtual memory settings as given below.

  1. Open the Control Panel on your computer.
  2. Click System and Security followed by System and then Advanced system the settings to open the System Properties
  3. Click the Advanced
  4. In the Performance section, click the Settings button to open the Performance Options
  5. Click the Advanced
  6. In the Virtual memory section, click the Change button to open the Virtual Memory
  7. Select the Automatically manage paging file size for all drives

You can also click the No paging file option button if needed and click the Set button.

  1. Restart the computer.


Virus threat

If your desktop or laptop is infected by malware or virus, the disk usage may be abnormally high. Run an antivirus program to get rid of the harmful file.

Make sure that you keep an eye on the scanning process. If you find the scan stopping partway, wait for a while to check if the scan resumes automatically.

If it doesn’t consider doing a reinstall or an update of the antivirus software, try using another antivirus software.


Third party software conflict

This conflict often happens when you have third-party antivirus software installed in your computer apart from the standard Windows Defender program that comes pre-installed with Windows 10 operating system.

Windows Defender usually gets disabled automatically when there is third-party antivirus. If this does not happen, a conflict tends to take place. Disable Windows Defender through the Settings window. Ensure that the real-time and cloud based protection options are turned OFF as well.


Is a high disk usage bad?

Yes, high disk usage can be bad. This can slow down the speed at which your computer operates, resulting in some processes becoming non-responsive and sluggish.

As a result, you will not be able to do any other task on your computer until these sluggish and non-responsive tasks complete their execution.


High disk usage


Why is my disk usage so high during startup?

Disk usage is high during startup mainly because the SysMain utility is enabled. This causes high disk usage during the read/write process and is not an essential utility. This can be disabled by clicking the Start button and typing services in the search bar.

In the Services window, locate the SysMain utility and double-click it to open the SysMain Properties window. Click the Stop button in the Service status section and close the window. In the Services window, set the Startup Type field for the utility to Disabled. Restart the computer.


How to decrease disk usage

Disk usage is usually expressed in terms of percentage. When the percentage is very high, the disk is usually utilized by a specific task. The disk usage can be minimized in two ways through the Services window. These two methods of decreasing disk usage are given below.


Method 1

  1. Press the Windows and R keys together to open the Run
  2. Type msc in the Run field and press Enter to open the Services window.
  3. Locate the Windows Update service and right-click on it.
  4. Select Properties from the menu.
  5. In the General tab, select Disabled in the Startup type
  6. Click Stop followed by Apply and then OK.


Method 2

  1. Open the Services window as mentioned above.
  2. Locate the SysMain service and select it.
  3. Right-click on the name of the service and select Properties.
  4. Click the General
  5. In the Startup type field, select the Disabled
  6. Click OK and reset the computer.


Method 3

This method is not advisable if you have third-party antivirus software installed in your computer.

  1. Press the Ctrl, Alt and Del keys in unison to open the Task Manager
  2. Click the Startup
  3. Select each process except Windows Defender one by one and click the Disable
  4. Close the Task Manager


Why is my disk usage at 100%?

Your disk usage is at 100% because of overworking of the hard drives. This happens because of a service running in the background or your computer is infected by malware.

You can try disabling the Windows Search and SysMain services temporarily through the Services window or by using the net.exe stop command for each service separately in the Command Prompt window. You must also run an antivirus software to get rid of any malware or virus in your computer.


Why does my disk usage spike from 0 to 100%?

Your disk usage tends to spike from 0 to 100% because you have a lot of data being written on to the computer while having low RAM.

Sometimes, a Windows Defender, Google Chrome and/or Skype setting can also cause the problem.

You can try upgrading the RAM if your system has a low RAM capacity. You can also try opening the Windows Defender program, turning OFF the Real-time Protection setting and turning it ON again. Similarly, you can try clearing the Prefetch resources to load pages more effectively checkbox in Google Chrome settings. It’s also worth disabling Flash in Google Chrome. Select the ALL APPLICATION PACKAGES option in the Skype.exe Properties window and give it the Write permission.

Performing a clean boot of your computer through the System Configuration window may also resolve the data usage spiking problem. You will have to restart your computer after executing the clean boot


How to fix high disk usage 100%

High disk usage of 100% can cause your computer to slow down and depict sluggish performance. This will have a drastic impact on the system performance in the long run.

There are several ways you can resolve this problem by taking the required corrective action. It’s worth noting that some corrective measures take a longer time than others.

Furthermore, it may not be required to implement all of them to solve the problem.


The following steps walk you through the methods of fixing the high disk usage 100%:

  1. Restart the computer instead of doing a shutdown operation. The restart operation activates the system in a fresh state while the shutdown operation retains the original state.
  2. Check for system updates in the Update & Security section in the Settings window and do the required updates. The installed updates can help to enhance the performance of the hard drive.
  3. Run an antivirus program to scan the computer and keep it free from virus. Although the antivirus may be running in the background automatically, it’s worth making the antivirus do a manual scan of the hard drive for a likely infection. This can be a time-consuming process since the disk usage is already high when this takes place.
  4. Stop the Windows Search and SysMain services temporarily using the “net.exe stop Windows Search” and “net.exe stop sysmain” If you find that doing this solves the problem, you can disable them permanently as explained earlier.
  5. Change the energy option from Balanced to High Performance in the list box in the Power Options You can access this window through Control Panel by navigating to Hardware and Sound followed by Power Options and then clicking on the Change plan settings and Change advanced power settings links respectively.
  6. Uninstall your antivirus software to see if it helps to resolve the issue. If it does, it’s recommended that you opt for another antivirus package as it’s not safe to have an antivirus package not installed in your computer.
  7. Reset the virtual memory of your computer as mentioned above. This is because the disk is treated as RAM by the virtual memory when the actual RAM capacity is low.
  8. Do a check disk to determine physical problems in your hard drive, if any. Analyze the results and take the necessary corrective measures.
  9. Change the Google Chrome and Skype settings as highlighted in the earlier section.


Why is my disk usage so high with nothing running?

Your disk usage is so high with nothing running because of the default Windows Defender antivirus software that comes preinstalled with Windows operating system. Sometimes the Windows Search and SysMain services can also cause a problem. Disabling these services or turning them off temporarily can fix the problem.


What should my disk usage be when gaming?

Your disk usage depends on the game you’re playing. The disk usage will be slightly higher than usual when gaming. It’s also possible for the disk usage to spike to 100% at times during games.

However, if the disk usage continues to be 100% for long hours at a stretch, it is likely that the hard drive gets corrupted or dies out due to heat.


Should disk usage be higher than GPU?

It’s ideal that disk usage should not be higher than that of the GPU. However, when you play games or watch videos, the disk usage tends to be more than that of the GPU if you have a low capacity GPU.

It’s recommended that you have a high capacity GPU to avoid high disk usage if you use your computer for such activities.


Why is disk usage higher than GPU?

The disk usage is higher than GPU because the graphics quality has been set to high. High quality settings can lead to low FPS that can in turn pave way for disk usage being more than GPU.

To solve this issue, it’s better to opt for low or medium quality graphics settings.


How to lower disk usage in games

High disk usage is a common problem when playing games, especially if the resolution has been set too high.

When the GPU doesn’t have sufficient capacity, the disk usage will be high and can damage the hard drive if it continues to be high for an extended period.

You can try lowering the disk usage when playing games by following one or more of the steps mentioned below.

  1. Run an antivirus program to remove an infected malware or virus in your computer. You can either opt for Microsoft products like Windows Defender or Microsoft Safety Scanner or use third-party antivirus software.
  2. Do a check disk operation by opening the Command Prompt window in admin/elevated mode and entering the chkdsk /x /f /r command at the command prompt and pressing Enter. You must type Y to confirm the check and reboot the computer to check and fix the errors on the hard drive.
  3. Disable the SysMain and Windows Search services in your computer. Make sure that you disable the hibernation mode as well.
  4. Do a clean boot of your computer and play games in that mode so that only essential and basic services run. This mode also prevents third-party applications from causing any issue.
  5. Do a general check of your disk for bad sectors and other problems. To perform this check, you should open Windows Explorer and check each drive individually. Right-click on each drive and select Properties to open the Properties window. Click the Tools tab and click the Check


Why is disk usage too high while playing Fortnite?

The disk usage is too high while playing Fortnite mainly because the RAM tends to get full and the system pagefile is being used by the drive. This issue can be resolved by carrying out the steps outlined here.

  1. Open the Fortnite game and open its settings.
  2. Go to the game settings and turn off the Record Replays option at the bottom.
  3. Close the settings and quit the game.


If you use an NVIDIA graphics card in your computer and have NVIDIA Experience installed, you must open it and disable the Highlights Replay option as well.

Once you’re done with these steps, proceed to carry out the steps mentioned earlier like disabling Windows Search and SysMain services to lower the disk usage.


Why is disk usage maxed out while playing Minecraft?

The disk usage is maxed out while playing Minecraft due to a faulty hard drive that must be set right. If you’re experiencing this problem with the hard drive in good condition, you can try the steps mentioned below.

  1. Check if your graphic card drivers are updated to the latest version and do an update if needed. You can access your graphic card drivers through the Device Manager
  2. Delete the temporary internet files of your browsers. This method helps only if you’re playing the browser version of the game.
  3. Allocate more RAM for the Minecraft Client. This will prevent the virtual memory from considering the disk as RAM and using it.
  4. Do a disk cleanup and disable unwanted processes running in the background.


Why is my disk usage high while playing Battlefield 2042?

Your disk usage is high while playing Battlefield 2042 due to an unused connected controller, conflict with third-party software or overclocking. The steps listed below can help you to get rid of the high disk usage problem.

  1. Remove unwanted USB controllers and USB devices connected to your computer while playing the game. They can result in a spike in disk usage.
  2. Play the game in a clean boot environment and check for optimum disk usage. If the usage appears normal, launch the third-party applications one by one and observe what causes the spike. You can disable those applications alone when you’re gaming.
  3. Check if you have opted for overclocking to boost the game performance and lower the clocking frequency. The overclocking can also cause the disk usage to rise high.


How to lower disk usage Windows 10

Disk usage in a Windows 10 computer is usually high because of a pending restart or Windows 10 update, malware, antivirus or antivirus software or a virtual memory problem. Unwanted applications can also trigger the spike.

You can lower the disk usage on a computer with Windows 10 operating system by following the steps given below.

  1. Restart the computer to flush its RAM and free it of undesired the short-term data and tasks. A restart also helps to enhance performance by plugging the memory leaks.
  2. Install antivirus software to clean the system of any potential virus or malware. It’s better to disable the pre-installed Windows Defender if you’re using third-party antivirus. However, if an antivirus program is the reason for high disk usage, you must uninstall it and enable Windows Defender once again.
  3. Make sure that the Windows 10 operating system installed in your computer is updated to the latest version.
  4. Uninstall Adobe Flash Player from your computer. Flash Player updates take up undesirable disk space and result in Windows disk usage spiking to 100%.

Apart from these steps, you can try the other options mentioned in the earlier “How to fix high disk usage 100%” section.


How to lower disk usage Windows 11

High disk usage in a Windows 11 computer is attributed to multiple factors such as multiple programs launch at startup, incorrect virtual memory, one or more malware or virus infected files, disk drive error or outdated drivers.

The following steps can guide you on lowering the disk usage in a Windows 11 computer.

  1. Do a full system scan using the latest version of third-party antivirus software. However, in some cases, the third-party software may be the reason for high disk usage. In such cases, uninstall the software and activate the inbuilt Windows Defender software.
  2. Disconnect external media storage devices like hard disks and pen drives from the computer.
  3. Disable the Windows Search and SysMain services either temporarily or permanently as detailed earlier. You can also consider disabling Windows notifications in the System section in the Settings
  4. Reset the virtual memory of your computer by following the steps given above.
  5. Clean the temp files and temporary Internet files from the respective folders on a regular basis.
  6. Fix the sys driver. This involves disabling the storahci.sys file from the registry. To do this, you will have to first locate the IDE ATA/ATAPI Controllers node in the Device Manager window. This method will not work if the window doesn’t have an entry.

Some of the steps mentioned for Windows 10 are applicable for Windows 11 as well.



It’s alright for the disk usage to occasionally be very high during operation. However, this should not always be the case as it can have a detrimental effect on your computer. You must take necessary steps such as restarting your system often and running antivirus software regularly to prevent unwanted spikes in disk usage.

Ernie Lo

Ernie Lo is a qualified web designer and web developer. He works as an IT support technician and website manager at Benleigh Vending, and he also fixes vending machines.

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