How to repair Unity registry on Windows 10? - unity3d

Question

I use PlayerPrefs to save some user data. I know that on Windows the data is actually saved in the registry under the \HKEY_CURRENT_USER\SOFTWARE\Unity\companyname key.
It used to be like this:
Unity
|--BugReporterV2
|--UnityEditor
|--companyname
|--some other things that I don't remember, maybe the project name then some detailed values
|--WebPlayer
I was intended to set all PlayerPrefs to default, so I deleted the whole key of companyname - stupidly without backup. Then in testing, I found that when calling
PlayerPrefs.SetString("testKey", "test");
it raised an exception
PlayerPrefsException: Could not store preference value
How can I repair the structure of the registry?
Can someone show me how the registry saved data with PlayerPrefs looks like under the "Unity" key with each keys and values please? Maybe I could fixed it manually.
Thank you!

Answer 1

I tried reinstall unity, and the registry is fixed. The origininal clean registry looks like this:
Unity
|--BugReporterV2
|--UnityEditor
|--WebPlayer
|--companyname
|--Project Name with Space
|--unity.cloud_userid_xxxxxx // value is quite complicated
|--UnityGraphicsQuality_xxxxxx // value is 5
The xxxxxx is something special for windows 10 that I'm not familiar with. Seems each key is followed by such a string that looks random to me. For anyone encountered similar issue, I think you can try creat the companyname and project name key. If the other keys are not created automatically after you run the project, then you could try reinstall unity.