The Windows 10 operating system is the latest version of Windows which was first released in 2015. It was made as a free upgrade to people who were running Windows 7 or Windows 8 on their computers. Although this is a solid performing operating system there are instances when certain issues can occur which we will be troubleshooting today. In this latest installment of our troubleshooting series we will tackle the windows 10 high cpu usage by .NET Runtime Optimization Service issue. How To Fix Windows 10 High CPU Usage by .NET Runtime Optimization Service Issue Before performing any of the recommended troubleshooting steps listed below it’s best to restart your computer first. This action refreshes the operating system and remove any corrupt temporary data that could be causing the problem. The .NET Runtime Optimization Service is a process that precompiles .NET assemblies in the background. Once it is done with its task it usually disappears. There are however instances when it will take a long time for it to finish its task which will cause this problem. Listed below are the troubleshooting steps you need to do to fix this issue. Speed up the process The first thing you should do in this case is to make sure that the .NET Runtime Optimization Service does its task quickly. You can do this by assigning more CPU cores to aid it in its task. Search for “Command Prompt” from the search bar. Right-click on the first result which appears at the top and select the “Run as administrator” option.Copy and paste the commands shown below and make sure you click the Enter key on your keyboard after each one. For the first two commands, choose the one according to your operating system (32-bit for the first one and 64-bit for the second one).Type cd c:\\Windows\\Microsoft.NET\\Framework\\v4.0.30319 then press enter ( for 32 bit systems)Type cd c:\\Windows\\Microsoft.NET\\Framework64\\v4.0.30319 then press enter (for 64 bit systems)Type ngen.exe executequeueditems then press enter Check if the Windows 10 High CPU Usage by .NET Runtime Optimization Service issue still occurs. Check for Malware One of the main reasons why this problem will occur is if your computer if infected with malware. It is therefore a good idea to run a malware scan on your computer so as to eliminate this threat. The best way to do this is to use Malwarebytes which you can download from https://www.malwarebytes.com/. Once it is installed run a scan. Open Malwarebytes for Windows.To the left, click Scan > Scan Types.If the Scan tab shows a Your scan is complete message, click Close X to view the Scan Types.Select one of the three scan methods provided: Threat Scan, Custom Scan, Hyper Scan.If a malware is detected it will be quarantined or removed from your system. Check if the Windows 10 High CPU Usage by .NET Runtime Optimization issue still occurs. Restart the service Another quick way to fix this problem is to simply restart the .NET Runtime Optimization Service. Open the Run utility by using the Windows Key + R key combination on your keyboard Type “services.msc” in the newly opened box without the quotation marks and click OK in order to open the Services tool.Find the .NET Runtime Optimization Service on the list, right-click on it and select Properties from the context menu which appears.If the service is started, you should stop it by clicking the Stop button in the middle of the window. Run it again by clicking the StartMake sure that the option under the Startup type menu in the service’s properties window is set to Automatic before you proceed with other steps. Confirm any dialogue boxes which may appear when changing the startup type. Check if the Windows 10 High CPU Usage by .NET Runtime Optimization Service issue still occurs.