Ever since the launch of Windows 10 back in 2015, Microsoft has been allowing PC users to download Windows 10 ISO directly from Microsoft using the official Media Creation Tool, and the same tool can be used to upgrade Windows 7/8 installation to Windows 10. At times, while opening the Media Creation Tool, you might get “There was a problem starting Setup. Close the tool, restart your PC, and then try running the tool again” error message. The error message usually shows up if you previously closed the Media Creation Tool while it was downloading an ISO or while it was trying to upgrade your current installation to Windows 10. If the error “There was a problem starting Setup. Close the tool, restart your PC, and then try running the tool again” is appearing, you can try out the given below solutions to fix the error and use the Media Creation Tool without any issues. We recommend you restart your PC once and try running the tool again before trying out given below solutions. Solution 1 Run the Media Creation Tool as admin As a first step, we recommend you try to run the Media Creation Tool as administrator. Solution 2 Run Windows Update Troubleshooter Running the Windows Update troubleshooter usually fixes this issue. To launch the troubleshooter: Step 1: Open the Control Panel. Change the View by to Small icons. Step 2: Click Troubleshooting to open troubleshooting window. Step 3: On the left-pane, click View all to see all built-in troubleshooters. Scroll down to see Windows Update troubleshooter. Double-click on the same to launch it. Follow the on-screen directions to complete the troubleshooting. Alternatively, navigate to Settings app > Update & security > Troubleshoot to launch Windows Update troubleshooter. Solution 3 Delete $Windows.~BT & $Windows.~WS folders In the root of your Windows installation drive, you could see two folders called $Windows.~BT & $Windows.~WS. These folders are hidden by default, so you need to configure the File Explorer to show hidden items to see them. Deleting these folders might also help you fix the issue. Refer our how to delete $Windows.~BT & $Windows.~WS folders in Windows 10 guide for step-by-step directions. Solution 4 Download Windows 10 ISO without media creation tool If the error appears even after trying solutions given above, download the Windows 10 ISO from Microsoft without the Media Creation Tool. If you are looking to upgrade to Windows 10, download the Windows 10 ISO file, mount the ISO, and then launch the setup file.