Hello, I understand that you're experiencing some issues with Firefox on your Windows 10 system. As a Firefox support volunteer, I'm here to help you troubleshoot and find a solution to your problem. To address the high CPU usage, mouse delays, and high power consumption, let's start with some basic troubleshooting steps: Clear the browser cache: Go to the menu (three horizontal lines in the upper-right corner) and select "Options." In the Privacy & Security section, scroll down to the Cookies and Site Data section and click on "Clear Data." Make sure to select both the "Cookies and Site Data" and "Cached Web Content" options, then click "Clear." Disable or remove problematic extensions: Extensions can sometimes cause performance issues. Go to the menu, select "Add-ons," and go to the Extensions section. Disable any extensions that you suspect may be causing the problem. If the issue persists, you can try removing them altogether. Update Firefox: Make sure you're running the latest version of Firefox. Go to the menu, select "Help," and choose "About Firefox." If there's an update available, Firefox will automatically download and install it. Create a new Firefox profile: Sometimes, issues can be related to your profile. To test this, you can create a new profile and see if the problem persists. Instructions on how to create a new profile can be found in the Firefox support article "Use the Profile Manager to create and remove Firefox profiles." If the above steps don't resolve the issue, it would be helpful to provide more information. For example, are there any specific websites or tasks that cause the high CPU usage? Have you noticed any recent changes or updates to your system that could be related to this issue? Please provide these details, and I'll be happy to assist you further in resolving the problem with Firefox. Best regards, Firefox Support Volunteer