We appreciate the time and effort you have put in to resolve the issue. I would like to assist you with further information from here.
Before proceeding as an initial recommendation, please check for the amount of hard disk space remaining, as the available free space is also responsible for Windows to run at optimal level of performance. Additionally, also check if similar issues persist
with other user accounts as well (if any).
Now please follow the below methods and check for the results.
Method 1
Place the computer in a Clean Boot state and check if there are any third party applications to be causing the slow down.
1. To disable all non-Microsoft services consult the article called
Clean Boot.
Note: After troubleshooting, refer to this section "How to reset the computer to start normally after clean boot troubleshooting"
Disclaimer: A clean boot is performed to start Windows by using a minimal set of drivers and startup programs. This helps eliminate software conflicts that occur when you install a program or an update or when you run a program in Windows. You may
also troubleshoot or determine what conflict is causing the problem by performing a clean boot. You must log on to the computer as an administrator to be able to perform a clean boot. Your computer may temporarily lose some functionality when you perform a
clean boot. When you start the computer normally, the functionality returns. However, you may receive the original error message, or experience the original behavior if the problem still exists. If the computer is connected to a network, network policy settings
may prevent you from following these steps.