Service Host: Agent Activation Runtime may show high CPU usage if the sound driver of your system is corrupt or the audio service is in the error state. Moreover, the wrong configuration of the Cortana may also cause the error under discussion.
The issue arises when the user’s system becomes sluggish and when he checks the Task Manager, he finds out that the Service Host: Agent Activation Runtime is using an excessive amount of the system’s CPU and memory.
Before proceeding with the detailed solutions to fix service host high CPU and RAM usage, check if performing a cold start (not restart) of your system resolves the problem. Also, as a temporary fix, you can end the Agent Activation Runtime process through the Task Manager. Moreover, some users reported that ending the Agent Activation Runtime process thrice (whenever it resurfaces after a system reboot) solves the issue for that session.
Solution 1: Disable and Enable the Audio Service
Agent Activation Runtime may cause high CPU usage if the audio service of your system is in an error state as Cortana (the Runtime calls the Cortana) is dependent on the audio service. In this context, temporarily disabling the audio service and then enabling it may clear the glitch and thus solve the problem.
- Press the Window key and in the search box, type: Command Prompt. Now, hover your mouse over the Command Prompt, and in the right pane of the Start menu, choose Run as Administrator.
- Now execute the following one by one (make sure to press the Enter key after each):
net stop audiosrv net start audiosrv
- Now exit the Command Prompt and check if the CPU usage of the Agent Activation has decreased.
Solution 2: Sign Out of Cortana and Disable it at the System’s Startup
The Agent Activation Runtime issue may arise if the Cortana is continuously being called by the Agent Activation service. In this case, signing out of the Cortana and disabling its launch at the system’s startup may solve the problem.
Sign-out of the Cortana
- Press the Windows key and in the search, type and open Cortana. You may also use the Cortana button on the Taskbar (if present) to launch Cortana.
- Now, in the Cortana window, click on the three horizontal ellipses (near the top left of the window) and choose Sign Out.
- Then, confirm to sign-out of the Cortana and right-click on the Taskbar.
- Now, in the menu shown, uncheck the option of Show Cortana Button and check if the Agent Activation Runtime usage is back to normal.
Disable Cortana at the System’s Startup
- Right-click on the Start menu button (which will launch the Quick User menu) and choose Task Manager.
- Now, in the Startup tab, select Cortana and click on the Disable button (near the bottom right of the Task Manager window).
- Then, press the Windows key and in the search box, type: Cortana. Now, right-click on the result of the Cortana and choose the App Settings.
- Now, under the option of Runs at Log-in, disable Cortana by toggling its switch to the Off position and reboot your PC.
- Upon reboot, check if the Agent Activation Runtime issue is resolved.
Solution 3: Reinstall the Sound Driver
The high CPU usage by Agent Activation Runtime may be caused by the corrupt sound driver of your system as it is essential for the operation of Cortana (which is the process called by the Runtime continuously). In this context, reinstalling the sound driver of your system may solve the problem.
- Firstly, make sure that you have downloaded the latest version of the sound driver of your system from the OEM website.
- Then launch the Quick Access menu by right-clicking on the Start menu button and then choose Device Manager.
- Now, spread the option of Sound, Video, and Game Controllers and right-click on your audio device.
- Then, in the mini-menu, choose Uninstall Device, and in the window shown, checkmark the option of Delete the Driver Software for This Device.
- Now click on the Uninstall button and let the uninstall process completely.
- Once the uninstallation is complete, check if the system is clear of the Agent Activation Runtime issue.
- Then reboot your PC and let Windows install the default sound driver.
- Now check if the CPU usage by the Agent Activation Runtime is back to normal.
- If the issue persists, then install the driver downloaded at step 1 as administrator and check if the Runtime issue is resolved.
If the issue was resolved after uninstalling the sound driver but emerged back after reinstalling, then keep your sound device uninstalled/disabled (until you need it to use and then revert to uninstall/disable).
Solution 4: Disable the Agent Activation Runtime Service
The issue may arise if the Agent Activation Runtime service is in the error state or stuck in the operation. In this scenario, disabling the Agent Activation Runtime service may solve the problem.
- Press the Windows key and in the search box, type: Services. Then, right-click on the result of Services, and in the mini-menu, choose Run as Administrator.
- Then, right-click on the Agent Activation Runtime service. The service may have different numbers at the end for different users like Agent Activation Runtime_XXXXX (where XXXXX represents random letters/numbers e.g., 15831).
- Now select Properties and change the Startup Type to Disabled.
- Then click on the Stop button and apply the changes.
- Now reboot your PC and check if the Runtime issue is resolved.
Solution 5: Edit the System’s Registry
If the issue is still there or the Startup type of the Agent Activation Runtime service is greyed out, then you may edit the system’s registry to solve the problem.
Warning: Proceed with extreme care and at your own risk as editing the Registry of your system requires a certain level of expertise and if not done rightly, you may cause undying damage to your system/data.
- Firstly, stop the Agent Activation Runtime service (as discussed in solution 4).
- Now hit the Windows key and in the search bar, type: Registry Editor. Now, right-click on the result of the Registry Editor, and in the mini-menu shown, choose Run as Administrator.
- Then navigate to the following:
- Now, in the left pane, select the AarSvc registry key, and in the right pane, double-click on the Start value.
- Then change the value to 4 and close the dialogue box.
- Now, in the left pane, select the registry key AarSvc_XXXXX (where XXXXX are some random letters/numbers) e.g., AarSvc_974ea, and in the right pane, double-click on the Start value.
- Then change the value to 4 and close the Registry Editor.
- Now reboot your PC and hopefully, the Agent Activation Runtime issue is resolved.