What is the Windows csrss.exe file and process?

Updated: 05/05/2017 by Computer Hope

What is csrss.exe?

Windows csrss.exe fileA Microsoft Windows file stored in the c:\windows\system32 or c:\winnt\system32 directory that has the file description: "Client Server Runtime process."

Is this file a spyware, trojan, or virus?

The csrss.exe file included with Microsoft Windows is not spyware, a trojan, or a virus. However, like any file on your computer, it can become corrupted by a virus, worm, or trojan. Antivirus programs can detect and clean this file if it has become infected. Because this file is part of Microsoft Windows, users should never delete or remove this file if they think it is infected. Let the antivirus program handle it.

Is it safe to remove csrss.exe from the Task Manager processes?

No. The csrss.exe is a critical system process that cannot be removed from the Task Manager without causing issues with Windows. When attempting to End Task csrss.exe, you will receive the Unable to Terminate Process window with the error "This is a critical system process. Task Manager cannot end this process." It is normal to receive this error.

The csrss.exe file is using 99%, 100%, or other high abnormal percentage of CPU.

The high CPU percentage usage issue is caused when your Microsoft Windows profile is corrupt. To resolve this issue requires that you delete and recreate the profile. To do this follow the steps below.

  1. Backup all the files in My Documents as they will be lost. It's also recommended you backup any other important files you may be concerned about losing.
  2. Log out of the account that is causing the problem and log into a different account. If you do not have another account, you can create a new account through the User Accounts icon in the Control Panel.
  3. Once logged in to the other account, right-click the My Computer icon and click Properties.
  4. In the Properties window, click the Advanced tab.
  5. On the Advanced tab, click the Settings button under User Profiles.
  6. Finally, in the User Profiles window, highlight the name of the profile that is encountering this issue and click the Delete button.

Once the profile has been deleted, you can recreate it if you want to use the same profile name.

Additional information

  • See our file definition for further information and related links on this term.