CPU Speed stuck at 0.78 GHz, How do I increase it to its base speed of 2.30 GHz?
Solution 1:
This is a known bug with Windows 10 20H2.
You will either need to rollback your latest update, figure out a way to install KB4580364, or wait for Microsoft to give you a fix using the regular update mechanism.
Here is a page confirming the problem: https://windowsreport.com/windows-10-slow-cpu-frequency/
Here is the Microsoft page that shows ways to get the patch: https://support.microsoft.com/en-us/help/4580364/windows-10-update-kb4580364
PLEASE NOTE that this fix is still BETA (preview) software. You need to ask yourself if you want to install another guess at a fix or roll back.