A “Disk Write Error” while downloading or updating a game in Steam has several possible causes. Luckily, a majority of them aren’t indicative of a serious problem with your PC. In most cases, a disk write error occurs because of a permissions problem or file corruption and can be easily resolved.
Restart Steam and Your PC
It’s a cliché for a reason — turning it off and back on again works. If you suddenly experience a disk write error, try restarting Steam. Right-click the Steam icon in the system tray (notification area) on your taskbar and click “Exit.” You can also click Steam > Exit in the Steam application window.
If restarting Steam doesn’t work, restart your PC. Restarting your computer reinitializes hardware drivers, ends all of the running programs, and clears the memory. If the disk write error was caused by an error with Windows (or any other operating system,) there is a good chance restarting your computer will fix it.
Check Write Permissions
A team disk write error could also be due to a permissions issue. If a Steam library folder has been set to read-only, or the user account you run Steam from doesn’t have write permissions for the library folder, Steam can experience a disk write error. Let’s check and see if that is the problem.
First, close Steam if it is running. Then, right-click the icon you normally use to launch Steam and click “Run as Administrator.”
Try the download again. If it works, you have a permissions problem. If that didn’t solve the issue, you can skip ahead to one of the other sections — the instructions in this one aren’t relevant to you.
Always Run Steam as Administrator
The first — and easiest — way to fix a permissions problem is to always run Steam as administrator.
Right-click your Steam icon and click “Properties.”
Go to the “Compatibility” tab, tick “Run as Administrator,” then click “Apply” and “Ok.”
Note: Running Steam as administrator like this will cause Steam to warn you that it is running in compatibility mode. As long as you only set it to “Run as Administrator,” you can safely ignore that message.
Change the Permissions for Your User
For security reasons, it’s not a great idea to always run applications as administrator if you can help it. However, the second solution is more involved. Every file and folder in Windows has user-specific permissions. If something has gone wrong between your user and the Steam folder (or any sub-folders), you can fix it manually.
First, you need to navigate to your Steam folder. It is located in “C:\Program Files (x86)” by default. Right-click the Steam folder and hit “Properties.”
Make sure the box for “Read-Only” is not ticked. If “Read-Only” is enabled, untick it, and click “Apply.”
Check the write permissions while you’re in the Properties window. Click on the “Security” tab, located along the top. Scroll through the list in the “Groups or User names” section and select your user. Look at the portion of the window labeled “Permissions for Users.” This is what controls all of the permissions for the folder, sub-folders, and files. All of the boxes should be ticked except “Special Permissions”. Don’t worry about that one.
If they aren’t all ticked, you need to force Windows to change the permissions for that folder, the sub-folders, and all of the files. Normally sub-folders and files will inherit the permissions of the folder that contains it, so you only need to change the permissions of the parent folder, Steam.
Click “Edit,” enable “Full Control,” then click “Apply” and “Ok.”
Clear Download Cache
The download cache is where Steam stores temporary files while a game or update is downloading or installing. Click Steam > Settings in the top left.
Click the “Downloads” tab, then, at the bottom, click “Clear Download Cache.”
You’ll be prompted to restart Steam. After the restart, try your download again.
Note: After clearing the cache, Steam will force you to log in again.
Repair Library Folder
If changing your permissions and clearing your download cache didn’t work, you can try repairing your library folder.
Click “Steam” in the top left corner of the Steam window, and select “Settings” from the drop-down menu.
Click “Downloads,” then click “Steam Library Folders.”
This window will show you all of the games you have downloaded. If you’re using multiple hard drives or multiple steam folders, they’ll be displayed here. Select the one that is giving you trouble by clicking it — it’ll be along the top. Then click the three dots on the right-hand side to open a drop down menu, and click “Repair folder.”
The more games you have installed the longer this will take, so be prepared to wait a few minutes. After it is done, attempt your download again.
Change Your Download Server
Though it is uncommon, sometimes the Steam download servers experience problems or outages. If that is the case, it can produce a variety of error messages. If you’ve tried all of the other steps, it doesn’t hurt to try changing your download server.
Click “Settings” in the top left-hand corner of the screen, then click “Steam Library Folder.”
Navigate to the “Downloads” page, then click the drop-down menu in the section titled “Download Region.” Normally, Steam will select the download server nearest to you. We need to change it to something else — try to pick something close to you.
If none of that works, you may have a problem with your hard drive. As a precaution, you should back up any irreplaceable or important files you have stored on the hard drive. Then you can try to fix the problem using chkdsk.