Solution 1: Remove Excel Add-ins

When you attach add-ins to Excel, they introduce additional functionality in the Excel spreadsheet. But the add-ins could be the reason behind the high CPU usage of Excel. To figure out this, you need to run Excel in Safe mode. If running Excel in Safe mode reduces CPU usage, then add-ins were indeed problematic. Follow the steps.

• First, you have to press and hold the Ctrl key and double-click on Excel to run it in Safe mode.
• Then, check the CPU usage of Excel.
• If the CPU usage decreases, remove all the Add-ins one by one.

Solution 2: Perform Clean Boot with your system

In some cases, the third-party applications that run in the background cause the high CPU usage issue. To solve this problem, you need to perform a clean boot on your system. Follow these steps given below.

• Click on the Windows Search bar.
• Type “msconfig” and press Enter.
• From the search results, choose the System Configuration option.
  
• Open the Services tab.
• Tick the box beside Hide all Microsoft services.
• When you click on the “Disable all” option, all the third-party applications will get disabled.
• Then, go to the Startup tab.
  
• Choose Task Manager.
• Stop all programs from starting when the system restarts.
• Save all the changes.
• Reboot your computer.

Solution 3: Update Microsoft Office

Microsoft Excel comes as a package with Microsoft Office. If there is something wrong with the Microsoft Office, then that will surely affect Microsoft Excel. The Microsoft Office updates come along with Windows updates. So, we are going to follow the steps for the Windows update and fix this problem.

• Press Windows key +I.
• Open Settings.
• Select the Update & Security option
  
• In the left pane, click on Windows Update, and in the right pane, click on the “Check for updates” option.

Solution 4: Fix damaged or corrupted Spreadsheet

Sometimes a damaged or corrupted Excel spreadsheet starts getting high CPU usage, and it can also create more problems. To fix the corrupted Excel spreadsheet, follow these steps given below.

• Type “Control” in the Windows Search bar.
• Click on “Control Panel” from the search results.
• Select Programs
• Choose the “Uninstall a program” option.
• Find and then right-click on “Office.”
• Select “Repair“
• After the Office installation is repaired, reboot your computer.

Solution 5: Delete Excel configuration files

If repairing Excel didn’t work, the problem may lie in the configuration files of Excel. You can try to manually delete the configuration files of Excel and see if that can fix the high CPU usage issue. Here’s a quick guide on how to find the configuration files.

• If you are using Excel in the background, make sure you close the Excel window before moving forward.
• Now, go to the following path in the Windows Explorer.
• C:\Users\Your Username\AppData\Roaming\Microsoft\Excel
• When you reach the Excel folder, copy everything from the folder.
• You can paste that content somewhere else for backup.
• Now, delete all the contents from the Excel folder.
• Reboot your system.
• Check the Excel CPU usage.

Solution 6: Uninstall Microsoft Office

If none of the above-mentioned solutions worked for you, then the last thing you should do is perform a clean reinstallation of Microsoft Office. But before that, you have to uninstall Microsoft Office. Follow these steps.

• First, back up your Microsoft Office license key.
• Download the Fixit tool.
  
• You only have to run the Fixit tool and follow its instructions.
• After you successfully uninstall Microsoft Office, restart your system.
• Install Microsoft Office again and check CPU usage.

 Microsoft Excel has created milestones for all the spreadsheet software out there. It is the most reliable and useful Office software. But even the most advanced programs can show some problems from time to time.